6 replies to this topic

[Badgers]

Hi guys, my 1.8T AUM has been off the road for over a year but yesterday took it for an MOT - it was running fine on the way but when I decided to accelerate hard all of a sudden it made like an aftermarket dump valve kind of sound, which it shouldn't as it has the standard vw dump valve, and since then it is hesitating really really badly under any load and making a slightly odd sound. There are no engine lights and no faults so far on the code reader and it actually passed its MOT fine including emissions test! It managed to limp home driving slowly at really low revs. When its warm strangely it actually idles ok and revs ok in neutral but from cold start the revs are now really up and down. Does anyone have any idea what the issue might be, it was running fine until that strange dump valve kind of sound, worried I've blown something?! Cheers!

[adam-]

Probably a boost leak somewhere.  Smoke test it to pin point it.  Use VCDS to check block 32 for trims.

[superchickenn]

As Adam suggests sounds like you've blown a boost pipe off somewhere 

[Badgers]

Probably a boost leak somewhere.  Smoke test it to pin point it.  Use VCDS to check block 32 for trims.

 

Thanks Adam! Just to clarify what does check block 32 for trims mean?! I've got a VAG code reader with 16 pin plug but no codes come up, is VCDS something else? Thanks for your help, much appreciated!

[thinkpad]

Thanks Adam! Just to clarify what does check block 32 for trims mean?! I've got a VAG code reader with 16 pin plug but no codes come up, is VCDS something else? Thanks for your help, much appreciated!

Block 32 is the long term and short term fuel trims. VCDS runs on a computer so your reader will be different. Some basic scanners/readers can look at live data such as the fuel trims (STFT, LTFT).

[Badgers]

Block 32 is the long term and short term fuel trims. VCDS runs on a computer so your reader will be different. Some basic scanners/readers can look at live data such as the fuel trims (STFT, LTFT).

 

 

Thanks!   Checked out the code list for my basic code reader and looks like it does read a few fuel trims:

 

Fuel Trim - Malfunction (Bank 1)

Fuel Trim - System Lean (Bank 1)

Fuel Trim - System Rich (Bank 1)

And the same for Bank 2, and also:

Long Term Fuel Trim - System too Rich (Bank 1)

Long Term Fuel Trim - System too Lean2 (Bank 1)

 

None of these show up though when I do the scan but sounds like there are other ones as well then per your message (e.g short term ones)?

I'll take a look at the boost pipes to see if anything looks split etc..

 

Cheers 

[adam-]

Generic scanners offer generic items.  Usually they're all CAN based and I don't see it correctly idenfifying VAG Blocks unless it's specifically a VAG tool.