I’m sure a lot of you are getting tired of seeing the same old questions being asked time and time again (eg MAF sensors, leaking washer hoses etc…) so I thought that it would be a good idea to post an FAQ / common faults thread, which will hopefully be made sticky . SO…….. as I’m a bit thick in terms of technical knowledge I’m hoping that you will help out by checking the info that I’ve posted below and letting me know of any mistakes I’ve made, other common faults, remedial action and, if possible, a link to a “how to”.

For everyone’s sanity, please help out!! PM me or post any advice here and I'll add it to the list. Ta.

Oh, as I don’t want to get into any trouble……. any advice given here is only a guide and is not to be taken as a diagnosis of a fault. If you decide to follow the advice given here, you do so at your own risk. Where possible, it’s easiest to run VAGCOM and check for any error codes.

My headlight / sidelight bulb has blown. How do I replace it?

Opinions differ on this one but I found it was easier to remove the bumper and the headlight unit to replace the bulbs. Others have done it in situ but it can be quite fiddly. This link will help with bumper removal.

Bulb replacement

My car has flat spots when accelerating.

Possible causes are a faulty or dirty MAF sensor, split turbo hose, faulty EGR or N75 boost control valves. These don’t always appear as faults on VAGCOM. MAF sensor appears to be the most common fault. Cleaning the MAF may help but ultimately, it needs replacing.

MAF Clean and MAF Replacement

How do I remove my OEM head unit?

Cut a sturdy but no longer required credit card/plastic card into 1cm strips lengthways. Insert these into the slots located on the left and right hand lower sides of the HU and it will unlock and you can then remove it.

My W8 Interior light rattles like mad with even moderate bass.

Take light out; split top cover from base unit by releasing clips; then remove lense from cover again by releasing clips. I superglued the lense back in and wedged small lumps of blu-tack between cover and body of light. (pikey but effective) and no more pesky rattles. Also useful if you want to colour code W8 light for an Anni as you only need to spray the cover.

My rear washer isn’t working.

It’s likely that the washer hose has detached, probably from the motor. Sometimes it can detach in the pillar / roof lining but you’ll probably notice a wet patch.

Washer repair (tailgate) or Pillar

My car keeps stalling / misfiring.

This could be caused by a faulty MAF sensor (again), temperature sender, relay 109 (diesels only), dirty throttle body, faulty coilpacks (petrol) or dirty contacts on the ignition amplifier.

Relay 109 - the sure-fire sign is when you try to start the car, the glowplug lamp stays out. After a few tries, glowplug light comes on, car starts

My window has fallen into the door.

The plastic window regulator has probably failed. Repair kits are available, which contain metal clips.

Window regulators

My central locking / door lock / alarm isn’t working.

This could be due to a faulty door lock module. You might be able to repair the faulty door lock by re-soldering the connections. Some people seem to have success simply spraying with WD40. Otherwise, it's a case of having to replace it.

Doorlock module

My windscreen wipers have stopped working.

The mechanism has probably seized. You can either replace the mechanism or strip it down, rub it with wet and dry and re-grease.

Wipers

There's a rattle when I accelerate.

This usually means the front or centre exhaust mount has snapped,small amount of welding needed or you could try using some large jubilee clips.

My cooling fans don't seem to be working correctly when the aircon is running.

Unfortunately, this is another common fault on the MkIV. I THINK it mostly affects the models that have climatronic aircon. To check if your fans are faulty, Andymac recommends the following:

1. turn engine on,
2. turn aircon on,
3. make sure ECON is "OFF"
4. Check fans are running constantly IE for more than 1-2 minutes
5. if the fans do nothing then run very fast, then stop after a minute or 2 or even 3 then you have faulty fans
Fans

My key-fob doesn't work

Assuming that the batteries are ok, it's likely that the key has lost it's code. If you have 2 keys, put one in the ignition and turn on (I'd lower the windows, just in case!), manually lock the drivers door with the other key. Press either/both buttons on the remote (alarm should chirp). Manually unlock the door and turn the ignition off. It should now be coded.

My rear seats and boot lining are wet

First of all, check the headlining. If that's wet as well, it's probably caused by the rear washer hose connection - click here for a fix. If it's not wet, it may be the rear vent seals that have perished - click here.

There's resistance in the steering followed by a strange twanging noise, especially when making slow, full lock manoeuvres.

Strut top bearings possibly seized.

Boot light doesnt work

Possibly a blown bulb but more likely the rear washer hose has popped off and soaked the boot catch. There is a microswitch in the mechanism that doesnt like getting wet. Remove the boot lid cover by undoing a screw in each handle on the inside, then pull the plastic cover to unclip. The boot catch then comes out by undoing the 2 large spline bolts. Try drying the switch with a hairdryer after stopping the leaking hose, or ultimately replace the whole boot catch. Can also cause the alarm to act strangely.

Heated mirrors don't work

First check to see if your car has them! Pop the mirror glass out by getting your fingers behind the outer edge and pulling, if there are 2 wires attached then they are heated. They are activated by turning on the rear window demister. Check to see if there is 12 Volts across the 2 wires, and/or check the fuse. If there is 12 Volts there and the glass doesn't get warm then the mirror glass needs replacing.

When I adjust the driver's wing mirror, the passenger mirror also moves but when I adjust the passenger mirror the drivers side stays still - is this a fault?
This is a feature not a fault, for convenience when adjusting for different driver height etc. To adjust mirrors, move the drivers side first (R) and then adjust passenger side (L) if necessary

The traction control light is coming on whilst I'm driving

This might also throw an alternator fault code also. The light will go out if the engine is switched off and back on. Follow the 2 small wires from alternator to a connector at front of gearbox, the wires break at that connector.

There's a clunking noise when I go over small bumps

Possibly caused by worn Anti-Roll Bar bushes.

EPC light keeps on coming on..
The epc light keeps coming on and goes when the engine is restared, this is a brake light switch failure. go to the stealers and give your chassis number over.. there are over 5 types and several revised version so the chassis number is needed.
INDICATORS sticking of flashing at random intervals
the indicators stick or dont flash with an equal time between them, the light relay has gone this is integrated into the hazard switch.. again a chassis number is needed

MkIV Door drop

You'll need the appropriate Spline bit that fits the hinge bolts (to fit a 1/2" or 3/8" drive ratchet), an extension bit at least 6" long (again 1/2" or 3/8" drive to suit the ratchet you're using) and an extra pair of hands! With the door open you should be able to reach the bolt furthest forward (TIP: get some 2" masking tape and mask the door edge and wing edge where you'll be working to prevent damage) you'll need to use the ratchet with extension bar insert it between the wing and front edge of the door and loosen the bolt. Now you'll need to release the kick panel trim inside the car (by the go faster pedal!) this requires you to unscrew the accelerator stop (the plastic lug under the accelerator pedal) now with a little pulling and manouvering you'll be able to get the trim off (WARNING: be aware that the airbag control box is behind this panel don't fiddle with the wires !) you should be able to get at the bolts now, a  torch can be handy here! Loosen the remaining bolts but beware i'd leave one slightly nipped up just so the door doesn't drop dramatically! now it's just a case of adjusting it untill the door fits correctly- don't expect to get it right first time though ! As soon as you've got it sussed tighten all the bolts and refit trim etc !

Common 1.8T Engine Problems

Thanks to GaryM for the following information.

Section 1. - Symptom - Possible Problem Parts (in order of likelihood)
Section 2. - Part Troubleshooting Method - Alphabetical

ctrl - F will help you search for keyword in this guide.

Section 1.
Rough Running At Idle - MAF, Ignition Coil, Spark Plug, VAC Leak, O2 Sensor, TB, CTS
Missfires under Boost Flashing CEL – Ignition Coils, Spark Plugs
Running Rich – Boost Leak, MAF, O2 Sensor, Coolant Temp Sensor
Running Lean – VAC Leak, MAF, O2 Sensor, Fuel Filter
Low Boost – Limp Mode, MBC, BOV, DV, Boost Leak, N75,
High Boost – MBC Setting, N75, Spark Plugs, Ignition Coils
Cold Start Problems – MAF, Spark Plugs, Fuel Pump Relay, CTS
Poor Gas Mileage – MAF, CTS, O2 Sensor, AIT Sensor
Cat Efficiency Below Threshold – Down pipe, CAT, Rear O2, RACE FUEL
No Start – Battery - ECU, Fuel Pump Relay, Ground
Start For 1 Second - Stall – Immobilizer
Overheating - Waterpump, Thermostat, Head Gasket
oil in coolant - Oil Cooler, head Gasket, Water Wetter
Dies While Driving Timing belt, Boost Leak, MISC
Shorts To ground CEL Fuel Pump Relay, Bad Grounds

Section 2 – Troubleshooting
Most of these procedures require a VAG com to scan the car for diagnostic codes. While you can fix things without a VAG you will most likely be replacing parts that really are not bad just to rule them out. A VAG COM is a must have for any 1.8T mechanic. Details here http://www.ross-tech.com/vag-com/cars/18T.html

AIT – Sensor – This is a small sensor located in the intake manifold just after the throttle body. It is responsible for monitoring the intake temperature. It can get coated with oil, and can affect gas mileage, and a loss of power. It is common to remove it and clean it with alcohol, or electronics cleaner.
Boost Leak – View Block 032 with VAG Com. If Fuel Trims are Negative more than 5% in the load range there is a very good chance that there is a leak after the turbo. Visual inspection of clamps, hoses for a loose connection is the best way to look for leaks. A common place for leaks is at the entrance to the pancake pipe located in the passenger side fender. Also the small line on the DV can rip.
Fuel Trim Details Here - http://www.ross-tech.com/vag-com/cars/fuel-trim.html
BOV – Blow off Valve’s vent off air metered by the MAF, and can cause many problems, and make it more difficult to troubleshoot a car. Best way to troubleshoot a BOV is to replace it with a DV and see if the problems continue.
CAT – Aftermarket high Flow Cats often sacrifice emissions for power. It is not uncommon for aftermarket cats to give codes for “efficiency below threshold” right away. Some people have had success using O2 adapters to move the rear O2 sensor away from the exhaust gas and eliminating this code. O2 simulators do not work on the 1.8T. Sometimes cats can melt or clog up. Running hig exhaust gas temps for extended periods of time can cause this. Usually you will get the cat code, and see that the max boost and sustained boost levels drop off. After checking everything else on the list, remove the down pipe/cat and check to see that light shines through brightly. If there is very little light passing through it is clogged and requires replacement.
CTS – Coolant Temp Sensor – This part is prone to failure. 2002 and older vehicles had a bad coolant temp sensor from the factory that VW updated. It was a black sensor, and now the good one is referred to as a green top coolant temp sensor. Block 011 in the VAG COM can monitor coolant temp for erratic readings. This is a 7$ part. Do not change while engine is hot.
Down-Pipe – See CAT
DV – Diverter Valve – When the throttle is closed on a turbo car, the turbo is spinning rapidly, and trying to push air into the engine. By closing the throttle the air has nowhere to go, and will cause a large pressure spike. The diverter valve is actuated by a vacuum line, and when the throttle closes creating vacuum behind it, the diverter valve will open and provide a path for the air. The air is returned back to the intake of the car after the MAF. When A DV fails it leaks air in this circular pattern causing boost problems.
2001 and older cars have a weak DV that is prone to failure. 2002 and newer cars have an improved design. It is durable, inexpensive (35$) and it responds very quickly. The part number for the good valve ends in 710 N. The DV is located at the back right side of the engine, it has 1 large hose, and 1 small line connected to it, and the other end is connected to your intake hose running to the airbox. To test if your DV has failed remove the DV, press the diaphragm up, put your thumb on the top nipple, and then release the diaphragm. There should be suction created on the top of the DV that prevents the diaphragm from returning. If there is no suction then the diaphragm is leaking and the valve should be replaced. IF the valve is good, check the VAC line leading up to the valve for any cut’s/ tears.
ECU – The ECU is responsible for nearly all functions on the car. If the ECU is suspected as a bad part, you need to use a scan tool such as a VAG com to attempt to communicate with the ECU. If you can’t communicate with the ECU, then the ECU needs replacement. Check all electrical connections. Check your Fuses for blown fuses. Whatever killed the ECU might kill the new one.
ECU removal procedure - http://www.goapr.com/VW/support/ecu_tt_golf_gti_jetta.pdf
Fuel pump Relay – The fuel pump relay is located under the driver’s side kick panel. Remove the lower panels to gain access to the relay box. When the fuel pump relay goes bad it will trigger many fault codes with electrical shorts to ground. The fuel pump relay is also used to turn on the injectors, and will show injector short to ground failures. If you open your door you hear the pump kick on, if the pump no longer kicks on, and you experience these codes repeatedly, replace the fuel pump relay.
Fuel Filter – The fuel filter on these cars is rated as a lifetime filter by VW. What the aftermarket has found is that high HP applications can run into fuel delivery problems with dirty fuel filters. 30K miles is a more realistic interval for replacement when pushing the system. The fuel filter is located under the car near the gas tank. It has small clip on hoses. To remove the hoses press in on the clip on the end of the hose and it will come off easily. You may need a small screwdriver for this, and be prepared to have fuel leaking out.
Head Gasket Head gaskets can be a cause of overheating, oil consumption or coolant in the oil. I have only heard of one case of a head gasket failure on a 1.8T and it was on a car running 30 lbs of boost and used head bolts. This is a repair better left to an experienced mechanic and is generally a last item to do after all other possibilites have been evaluated. overheating is usually the water pump, and coolant in the oil is usually the oil cooler failing internally.
Immobilizer – These cars are equipped with immobilizers to prevent theft. If you swap an ECU without matching up the ECU and the cluster, it will start briefly and then die repeatedly. There are 2 kinds of immobilizer. Immo II used on pre 2002, and Immo III used on 2002+. Immobilizer and ECU info can be found on the VAG COM Site.
http://www.ross-tech.com/vag-com/cars/immobilizer2.html
http://www.ross-tech.com/vag-com/cars/Immo3-ecu-swapping.html
If swapping an engine into a car without an immobilizer/cluster, you can get software for swaps from REVO, and Dahlback that remove the immobilizer.
Ignition Coils – These are famous parts for the 1.8T they are very prone to failure. VW has had a recall on these because they were failing rapidly on 2001+ cars. To check for bad coils the best way is with a VAG COM. Log Blocks 015, and 016. This will be a misfire counter. Drive the car or let it run, and look for misfires. If you have a bad coil you will see the counter increase on a cylinder. If you have one counting up then it’s probably a bad coil. Turn off engine and take that coil out and swap it with another coil. The cylinders read left to right 1,2,3,4 when looking at the engine from the front. Use the VAG again to see if the misfires have also swapped to another cylinder. If it moved, then you have a bad coil. Replace it. If they do not move, then you likely have a plug problem. On some cars the ignition coils have problems and they will pop up out of the cylinder head and lose contact with the plug. Plugs should be torqued to 22 ft-lbs when changed. If the coils still pop up, and they are torqued properly I have created a bracket kit to hold them down  – see sig.
Limp Mode – These cars are designed to protect themselves from engine damage. If the engine boosts too much, or the engine does not get enough fuel it will go into a limp mode where boost is limited to protect the engine. It limits boost by controlling a solenoid on the wastegate line (N75), by closing the electronic throttle or by opening the DV valve. If you are experiencing a limp mode the best thing to do is get the car scanned for codes and to see what is wrong. Look at fuel trims for signs of running lean, and to look for MAF problems, or O2 sensor problems. To look for potential boost problems log Block 115 and you can see the specified Vs actual boost. If you exceed the specified then there is a good chance that you will go into this limp mode. Stock specified is a max of 14 psi for a 2002+ car.
MAF – Mass air flow meter is used to measure the air going into the engine. It is located on the outlet of the airbox, and housed in a cylindrical tube. The ECU reads the MAF signal, and injects fuel in proportion to the airflow. There are a few different ways the MAF can fail. The MAF can get coated with oil, and will not read properly. This is common if it happens right after installing a CAI, or a K&N filter. It can be cleaned out with 99% isopropyl alcohol, or a quality electronics cleaner. Remove the sensor from the housing and clean the sensor element.
MAF sensors also go bad due to too much airflow. On a car with a larger turbo the airflow is so high that the MAF element will get burned out from the excess air flow. It is common to increase the size of the housing to prevent this (other modifications required).
To check for a BAD MAF the best way is with a VAG com. Block 002 show air mass from the sensor. At idle the air flow should be 2-4 grams/second. With a wide open throttle run to redline the reading should show up to 170 g/s on a chipped car. Look for jumpy readings in the MAF, which can indicate a problem. More details here http://www.ross-tech.com/vag-com/cars/fuel-trim.html if you suspect your MAF is bad, one way to test it is to unplug the MAF, often if the MAF is giving false readings and upsets the fueling. If you unplug it, the ECU will ignore the MAF and run off of baseline tables. Be careful, as a boost leak or a vacuum leak can be miss-diagnosed as a bad MAF, because they will throw off the readings on the MAF. (Air sneaks around the MAF).
MBC – Manual Boost Controller. Often people want more boost from their car, and use a MBC. While MBC’s can get you more boost they will cause a jerky part throttle driving, and can cause over boost, often put the car into a limp mode. The way a MBC works is by bleeding off air from the wastegate control line. A wastegate is a mechanical flapper valve in the turbocharger that opens to allow exhaust gas to sneak around the turbo. By bleeding off air from the line, the wastegate opens less, more exhaust goes through the turbo, and you get more boost.
Great details on MBC here - http://www.boostvalve.com/tech/1.8T-DBW.html
And general Turbo/Wastegate details here http://www.streetracersonline.com/articles/turbo/wastegate.php
N75 – The N75 is an electronic solenoid valve that the ECU uses to control boost. It is located in the intake hose near the back right side of the engine. It has 3 connections.
1. Connects to charge pipe = pressure source
2. Connects to wastegate actuator
3. Connects to intake hose – bleed line.
The ecu will pulse this valve at a high frequency to bleed air off from the wastegate line. It does this based on throttle position and engine load. If the valve, or any of the liens connected to it have leaks then there can be severe boost regulation problems. It’s function is similar to the MBC above. To get more boost people often swap in different N75 valves. These different valves simply have a different response characteristic, and will act different when given the same signal by the ecu. They can get more boost, less boost, or even a big boost spike by swapping N75’s.
O2 Sensor – Because of strict emissions these 1.8T’s are very sensitive to readings from the O2 sensors. MY 2001+ have a wideband front O2 sensor with high accuracy and a linear response. The car will adjust the fueling based on the readings from the sensor. If the sensor is over heated, exposed to lead (race gas), flooded with soot (too rich) or is just old, it can provide the car with false readings and the car will not provide the proper fueling. When the O2 sensors go bad and the ECU detects this the car will run on reserve fueling maps and will not be able to adjust for boost leaks, fuel pressure, MAF readings or any other parameter that affects fueling. To check for a bad sensor the first thing to do is run block 032 on the VAG com. If the sensors are bad, the readings will both be 0%, replace the Front O2 sensor. If the sensor is bad, it will also respond slowly, or reach a peak. Logging block 031 will show the lambda reading from the O2 sensor as well as the requested lambda from the ECU. To get air fuel ratio multiply lambda by 14.7. If the lgo shows the lambda jumping wildly when running through a gear, or perhaps it flat lines at an unreasonable level, then the O2 sensor should be replaced. It is a 50$ part. If the o2 sensors get shorted out or the wires get pulled, they will damage the ECU, be careful with the wiring on these sensors. 2000 and older cars do not have a wideband sensor, however they will still perform some adjustment of fueling based on the sensor.
Oil Cooler The Oild cooler on these cars uses a plate and plate heat exchanger. Oil on one side, coolant on the other side. Often the brazing on teh cooler can fail and oil and coolant mix together. This is often misdiagnosed as a bad head gasket. To test this remove the coolant hoses and apply air pressure to the oil cooler and watch for leaks. Oil cooler is located above the oil filter.
Spark plugs – With the weak coil packs that these cars have, and the high boost pressures that they run, the spark plugs are very important. Spark plugs on turbo cars need a nice tight gap 0.028” is recommended. Spark plugs may come “pre-gapped” however you should always check the gap, as the variation can be severe and will cause problems. Plugs are cheap, so the best way to troubleshoot is to replace them or pull them and check the gap. A good cheap replacement plug that is a bit cooler is an NGK-BKR7E copper plug. They need changing more frequently, however they are cheap.
Thermostat - Thermostats can be a source of overheating. Most common is the waterpump. Thermostats are relatively inexpensive, and can be change din a half hour. If your car overheats, or has a tendency to spike up in temp and then drop down to normal temp, it may be a thermostat.
Timing Belt If your driving along and your 60+K mile car runs great and all of a sudden dies, there is a good chance that your timing belt has broken, or stripped some teeth. This is a very costly repair and could have been prevented had the factory recommended a better service interval for the belt. Damage estimates are anywhere from 600 - 1800$ to repair this kind of failure. 60K miles is a good time to change the timing belt, some belts have lasted 90K, but it's not worth the risk. To test for this failure, pull off the timing belt cover and crank the engine by hand. If the cam gear doesn't turn you have a bad timing belt. Repair is best left to a good mechanic. - If your going full throttle and the car all of a sudden dies, check for a boost hose blown off -
TB – The throttle on these cars is drive by wire, it is an electronic throttle with a wire attached. Most common TB problem just requires adaptation, or cleaning out with carb cleaner. This procedure shows how to do a TBA. TBA can improve idle, and part throttle operation. http://www.ross-tech.com/vag-com/cars/throttlebody.html. To clean the TB remove it, and spray inside with carb cleaner. Wipe out the residue that gets built up in there. NEVER port a TB on a 1.8T it won’t idle properly.
Race Fuel – 1.8T engines love high octane fuel, however they can have cold startup problems, and if you run leaded race fuel you will ruin your Cat and your O2 sensors. Always run unleaded fuel in a 1.8T unless you are cat less, and you have extra o2 sensors.
VAC Leak – A VAC leak will cause un-metered air to enter the engine and it will run lean. If the air is not measured by the MAF then the fuel will not be injected. The O2 sensor will compensate for much of this, however it has limits. To check for a VAC leak, log block 032 and check the idle fuel trims. If it’s more than +2% you probably have a VAC leak somewhere. Check hoses and connections for loose clamps of cut hoses here are come common areas for VAC leaks.
Turbo inlet pipe not secured, DV line leaking, Crank case breather Y pipe split, Line on Fuel pressure regulator gets worn and leaks, intake manifold gasket can leak, and PCV line under intake manifold leaks. To find leaks some people spray ether, or starter spray around in the engine bay and listen for changes in idle speed. If you get a change from spraying in a certain area look for leaks there.
Waterpump - Nearly all overheating problems I have seen on these engines has been from the water pump. VW uses a plastic impellar that is splined/molded onto the shaft. These splines strip, or the pump cracks and the impellar slips on the shaft at high speeds. If your car is overheating best bet is to change the waterpump. You can do the T-stat first to see if your lucky but every time I have seen people try this it's the water pump anyways. This happens as early as 35K miles. While your in there doing the water pump, change the timing belt. Timing belts on these can go as early as 60K miles. There are several companies that make kits to do the timing belt and water pump. www.ecstuning.com is a good one.
Water wetter - Water wetter is an additive used to remove surface tension from water. It improves waters cooling ability in a cooling system as it prevents beading of the water, and raises the boiling point. Water wetter should not be used with G12 coolant. It is best for race cars running only water. If you add this to the coolant reservoir you get a nasty oily sludg in the reservoir. Flush coolant system and remove this.

 

Delocking - If you've not already done so, one of the best pieces of advice is to delock your Golf, leaving the boot lock as standard. Basically, delocking is a small disc that covers the keyhole. I'm not going to go into the reasons behind this but suffice to say it's a security issue. The kits are available from dealers.

Thanks to those that have contributed to the list and to the people who have written the original replies and links. Special thanks to GaryM who has contributed greatly to this.

Diesel owners - for another great source of info, click here

Slight rattle on acceleration usually means the front exhaust mount has snapped,small amount of welding needed. Have heard a few people mention it,not sure if that makes it a 'common' fault but mine's doing it ATM

Relay 109 applies to diesels only.

The sure-fire sign is when you try to start the car, the glowplug lamp stays out. After a few tries, glowplug light comes on, car starts.

Looks like a great start Dave

I'll make it sticky & hopefully more people will reply as well, adding new Q&As or expanding on what you have above. I think it would be best if you edited the original post to add questions in (so it's doens't get too confused), then get somebody to delete replies, what do you reckon?

The following items replaced under warranty at 24000 on my GT TDi 150 03 reg

New CD player

New Rear wiper motor

New Fan behind dashboard for air con

Cat1.4 wrote:

Looks like a great start Dave I'll make it sticky & hopefully more people will reply as well, adding new Q&As or expanding on what you have above. I think it would be best if you edited the original post to add questions in (so it's doens't get too confused), then get somebody to delete replies, what do you reckon?

Yeh, that's what I was thinking. Makes it a little easier, especially for newbies.

Cheers for the replies so far.

Spiker wrote:

The following items replaced under warranty at 24000 on my GT TDi 150 03 reg New CD player New Rear wiper motor New Fan behind dashboard for air con

Re. the wiper motor and new fan - what were the faults?

Great idea - especially for people who have only recently come onto the VAG scene such as myself.

A guide towards all common faults and how to go about fixing them is definately the way forward - looking forward to it!

Dont forget creaking doors on three door models and drooping doors due to hinge wear. Also fan failure on the climatronic cars!!!  Ahhhh VW build quality, Think ill buy a Cit**en next time!! ONLY JOKING, can u imagine how many faults you would have on this page with one of them.....

If you do have a diesel (esp. non-pd ones), a cracking source of info is http://www.tdiclub.com/

If you haven't already done so, spend an afternoon securing the hose joints on your rear washer with small cable ties, to prevent them popping off. There's two places, inside the rear hatch at the motor, and at the c-pillar.

Excellent idea.

On the centre exhaust mount problem. There is a fix which works well and doesn't involve welding. Not sure if people will like it or not but i got it originally from a VW specialist who use it regularly as they find welding isn't always sucessful. I did mine about 8 months ago (now a further 2 years @Dec07 and still never touched it) and it's still going strong, you simply buy two larg jubilee clips about 2 -2and a half inch size and clamp the bracket back on. Jubilee clips are better than exhaust brackets as they dont foul on surrounding parts. I don't know if this can be added on above, i wouldn't know where to start I am afraid.

Thanks

Wallace

On my R32 strut mount bearings replaced twice under warranty.

Problem

Resistance in the steering followed by a twang type noise especially when making slow, full lock manoeuvres eg reversing out of a drive way.

Resolution

Strut top bearings seized. Replaced by dealer under warranty.

Thats very interesting, I recently bought a full r32 front subframe with struts to go in my 1.8t and both strut top mounts were completely seized, This was from a 3,000 mile vehicle!!!, Will keep an eye on them. PS did u know you can lower the front of an R32 for free.....there are two billet alloy spacers fitted under the top mounts approx 10mm high, remove these and you lower the front by 10mm with no probs. VW used racing springs and probably thought the ride height too low for uk roads so fitted these spacers!!!, I dont think they are fitted to non uk cars...

Dirty ignition amplifier contacts don't always cause stalling, it can just be a misfire, as seen on my car.

Solution: Clean contacts with contact cleaner/white spirit or maybe some light wet 'n dry to remove any heavy dirt.

Here is a couple I have come across

Boot light doesnt work

Possibly a blown bulb but more likely the rear washer hose has popped off and soaked the boot catch. There is a microswitch in the mechanism that doesnt like getting wet. Remove the boot lid cover by undoing a screw in each handle on the inside, then pull the plastic cover to unclip. The boot catch then comes out by undoing the 2 large spline bolts. Try drying the switch with a hairdryer after stopping the leaking hose, or ultimately replace the whole boot catch. Can also cause the alarm to act strangely.

Heated mirrors don't work

First check to see if your car has them! Pop the mirror glass out by getting your fingers behind the outer edge and pulling, if there are 2 wires attached then they are heated. They are activated by turning on the rear window demister. Check to see if there is 12 Volts across the 2 wires, and/or check the fuse. If there is 12 Volts there and the glass doesn't get warm then the mirror glass needs replacing.

 

 

Just stumbled across this thread again - soooooo useful!

Going to use one of the guides to fix my rear washer jet!

Dave  - that is a really great start and will help lots of people.   I have a couple of minor comments - I believe that the cooling fan problems only affect the later cars (150s) as the fans are different on my PD115 - I,m not sure about the rest of the range - someone else may be able to confirm this.   On the subject of water pump problems it is possible to do a rough check on the impellor once the thermostat has been removed - if it it possible to turn the impellor there is obviously a problem.

Hi I am a newbie to the Golf scene having purchased my first MkIV Golf last week (2000X V6 4motion). Thanks for the excellent FAQ section, I would like to expand/ask an extra query re the wing mirrors - my electric near side mirror goes L and R fine but when adjusted for up and down it doesn't work but makes the off side mirror go up/down! This mirror incidentally works and moves in 4 directions just fine. I wonder if it is a fuse/connection problem or is it the way the mirror is fixed in the case??!! Many thanks and keep up the good work!

Another common problem, with the PD especially, not sure about the petrols. If your driving along and after a few miles the traction control light comes on and wont switch off until you turn engine off and on and which keeps happeneing everytime you drive, here is usually the cause, it will also give an alternator fault code also.

 Follow the 2 small wires from alternator to a connector at front of gearbox, the wires break at that connector. Its happened mine and others i know off.

micky 32 wrote:

Another common problem, with the PD especially, not sure about the petrols. If your driving along and after a few miles the traction control light comes on and wont switch off until you turn engine off and on and which keeps happeneing everytime you drive, here is usually the cause, it will also give an alternator fault code also.  Follow the 2 small wires from alternator to a connector at front of gearbox, the wires break at that connector. Its happened mine and others i know off.

Does anyone know if this is both petrol and diesel, or if it only affects the pd?

Hello All, New member, was referred by a friend. i have just bought a Mk 4 GOLF SE TDI PD i put £46.00 worth of diesel in. and the diesel gauge moved of its spot and went to the first stick within 40 miles" src="/emoticons/emotion-6.gif"> and apparently i was getting 49MPG, what could be the problem?? help please.

FAQ: This comes up all the time on the forum.

Q.How do I remove my OEM head unit?

A. Cut a sturdy but no longer required credit card/plastic card into 1cm strips lengthways. Insert these into the slots located on the left and right hand lower sides of the HU and it will unlock and you can then remove it. I'd put up pictures but no longer have a MKIV so can't.

W8 Interior light rattle.

Rattle like mad with even moderate bass.

Take light out; split top cover from base unit by releasing clips; then remove lense from cover again by releasing clips. I superglued the lense back in and wedged small lumps of blu-tack between cover and body of light. (pikey but effective) and no more pesky rattles.

Also useful if you want to colour code W8 light for an Anni as you only need to spray the cover.

 

Sammyboy and ct.p - thanks for the info. Both have been added.

Hi all
I am new here and would just like to say what a good idea it is for everybody to post all the problems and faults that have happend to them

I also have a MK4 golf and this one seems to have been built on a monday when nobody could be Ar*ed to do anythin.

It all started when i first got the car and it was stalling all the time so the ECU was replaced and at last there was peace and quiet that was in 2001 and at the end of 2004 my wife was driving when it started to miss and the dash lit up like a christmass tree
and after beaing towed to a VW dealer we found out the the engin had blown a hole through the top of a piston, but thanks to a very nice VW dealer in Germany we got a new engin at the cost of VW.

If that was not enough last year the unthinkable happend and the gear box kissed it´s bum goodbye due to a common and denied design problem that VW says does not exist, year right,for infomation GEARBOX CODE  ERT

but if anybody has found this out for themself then let me know as after not wanting to spend around 1500 quid on a new one i made a bit of a discovery and you will just love it and mine now has a gear box from an old VW VENTO.

THERE IS LOST MORE IF ANYBODY IS INTERSTED

many thanks
Andy

How to install an turbo timer

http://s90139951.onlinehome.us/vw/ttinstall.htm

One I have had on both my MK4 Golfs (TDI)- clunking noise from front of the car when going over small bumps- caused invariably by worn anti-roll bar bushes.(about £30 for parts)

I have a 1.4e S reg and its just done 70k yesterday. Seems to be running perfectly apart from two things. Its very sluggish is 1st so takes a lot of revs to pull away and it does this funny sort of "burp" thing every no and then. Say im on the motorway (doing no more than 70mph, of course), it will suddlenly drop revs from 3500 down to just over 1000 for a split second. It doesnt seem to affect the driving at all just puts the wind up me a bit. Its going it for its 70k service and a cam belt change next friday so any help before this would be brilliant.

Cheers

MkIV Door drop

I fixed mine by adjusting the lower hinge:

1. You'll need the appropriate Spline bit that fits the hinge bolts (to fit a 1/2" or 3/8" drive ratchet),
2. An extension bit at least 6" long (again 1/2" or 3/8" drive to suit the ratchet you're using)
3. An extra pair of hands!

With the door open you should be able to reach the bolt furthest forward (TIP: get some 2" masking tape and mask the door edge and wing edge where you'll be working to prevent damage) you'll need to use the ratchet with extension bar insert it between the wing and front edge of the door and loosen the bolt.

Now you'll need to release the kick panel trim inside the car (by the go faster pedal!) this requires you to unscrew the accelerator stop (the plastic lug under the accelerator pedal) now with a little pulling and manouvering you'll be able to get the trim off (WARNING: be aware that the airbag control box is behind this panel don't fiddle with the wires !) you should be able to get at the bolts now, a  torch can be handy here!

Loosen the remaining bolts but beware i'd leave one slightly nipped up just so the door doesn't drop dramatically! now it's just a case of adjusting it untill the door fits correctly- don't expect to get it right first time though !

As soon as you've got it sussed tighten all the bolts and refit trim etc !

It worked for me, and will save having a new hinge fitted ££££ !!

EPC light keeps on coming on..

The epc light keeps coming on and goes when the engine is restared, this is a brake light switch failure. go to the stealers and give your chassis number over.. there are over 5 types and several revised version so the chassis number is needed.

INDICATORS sticking of flashing at random intervals

the indicators stick or dont flash with an equal time between them, the light relay has gone this is integrated into the hazard switch.. again a chassis number is needed and it is a dealer only job

Idle/Stalling often when slowing down to turn - some Mk 1V's (ETKA doesn't seem to specify which engine codes but my car is a 1999 1.6SE) have an oil pressure sensor on the power steering pump which is linked to the idle stabilisation to boost the idle when power is sapped by the steering. If this fails the symptoms on the heading can occur and no fault seems to be reported in Vag-Com.. Couldn't find any info on this on the forum but thought it might be useful.

 

Chassis Nos 1J-Y-000-001 >         Sensor Part No 1J0 919 081

Chassis Nos 1J-X-990-000>         Sensor Part No  6N0 919 081 A

 

Just want to say how usefull this thread has been. I'm completely new to Golf MkIV ownership and not got much experience of VW's either, so all this info is very very usefull.

I thought I'd chip in after a fault I had this morning.

Everything lit up on dash as normal then nothing when you turn the key. Turns out the +tive had fallen of the starter solenoid. Doh! I know it's simple but the rubber cover round the spade held it in place so it wasn't obvious to look at. Only found it whilst going through the wire wiggle type check.

I also initially thought it was an imobiliser issue so I pulled the three main fuses for a reset. They were quite oxidised and when I replaced them I got an alarming message on the dash. "STOP brake failure see service manual". As you can imagine I was having a great morning when in a rush for work lol.
One of the main fuses obviously didn't have a good connection and after a good clean of the blades on the fuse everything was back to normal.

Maybe obvious but I thought I 'd post as I've been actively using this thread.

Thanks

Unsure if this is the best place to post this so here goes,

I have just had confirmed that an issue I thought was a problem with a CV joint ended up being an number of broken rivets at the crown wheel in my Gearbox. The car concerned is a Golf 1.6 8v 1999 with 60k miles on the clock. However the Specialist Gearbox Rebuilders say that this is a common fault. The issue relates more specifically to early 1.6 Golf's up to 2002. However I'm not sure if this is exact please see other posts in the gearbox & clutch section for more detail.

Basically VW have been using rivets instead of bolts on parts for there gearboxes since the 70's and as engines have got more powerful & torquey the rivets haven't been up to the job. VW do supply a fix kit which contains uprated bolts but do not consider it a cost effective to install these from the start rather than rivets.

The symptoms which lead to this discovery were.

A small wobble coming from the passenger side of the car, at first I thought this a problem with the CV joint or Driveshaft, very quickly this wobble got very much worse so that the car was almost impossible to drive above 15mph, there was no issue with the engine as it rev'd fine through the range in neutral and it even changed gear without problem. Additionally in later stages a large amount of grating/grinding could be heard which was the diff bearings & detached rivet heads eating themselves. The gearbox place has said that it's not uncommon for the rivets to get into the gearing mechanism and completely destroy the syncro's, gear wheels and even the gearbox casing.

The fix for a servicable gearbox is coming out at circa £700 exc VAT, otherwise it's a new unit at about £1.7k (unfitted)

Link to more info http://www.btinternet.com/~a_hutton/VW_Gearbox_Failure.htm

can we also add:

door lock pumps issue
wiper linkage siezing
water pump
reccomendations for delocking the drivers lock

R44MS_K:

can we also add:

door lock pumps issue - not sure what this is. Please would you be more specific re symptoms
wiper linkage siezing - already included
water pump - already included
reccomendations for delocking the drivers lock - will add

yea agree with that ment to be a common fault on 1.6 alk engines. just gone on mine mr clutch in gateshead quoted me £795 inc vat and labour [:'(]

Hi,

mk 4 gt tdi golf, occasional failure to start, first time I intially thought it was a fuel problem, turning the engine over brought on the STOP warning, checked oil level which was a little below the full mark on the dipstick, topped up oil which took no more a couple of capfuls, and everything was fine, car then starts and runs fine.

Should they car fail to start with minimal low oil showing on dipstick? or is the warning over sensitive?

The car uses very little oil, runs perfectly, yet will not start if oil level is slightly low, is this normal?

I apologise if this question has already been asked a thousand times -:) 

Petej

 

 

 

yeah my bora is the same.  i think that it may well just be a faulty sensor.

wallace:

Excellent idea.

On the centre exhaust mount problem. There is a fix which works well and doesn't involve welding. Not sure if people will like it or not but i got it originally from a VW specialist who use it regularly as they find welding isn't always sucessful. I did mine about 8 months ago and it's still going strong, you simply buy two larg jubilee clips about 2 -2and a half inch size and clamp the bracket back on. Jubilee clips are better than exhaust brackets as they dont foul on surrounding parts. I don't know if this can be added on above, i wouldn't know where to start I am afraid.

Thanks

Wallace

 

 

Great info my job for the weekend

I had this.  I fixed it by tipping 1/2 cup of car cleaner onto the throttle butterfly valve (engine cold and not running) - it runs past the valve and into the throttle body.  left it overnight, and then drove away with a smile on my face.  I assumed that it would not damage the cat - you might like to check!