Well I've taken the car out twice since getting it back from the garage. Strangely noticeable things are the car:
- still goes like stink and gives locals a run for their money on a roundabout or at the lights.
- even in the middle of nowhere, up a big hill a farmer driving a tatty mk1 Ford Focus will pass by leaning out the window saying 'Nice car!'
The first trip, I just drove it as normal and headed for the hills. Drove fine for 45 miles util I got about 1100ft up where the engine made a complain and engine light came on. Didn't have the reader with me but discovered the car ran better than it just did. Drove car back home on the A roads without issue.
Tonight though I decided to drive it in a more normal environment and see what it does and doesn't like. I cleared the engine light as you shouldn't bother reading it the first time round.
If you do the following, you can feel the power come back on all 6 cylinders:
- Change gear between 2.8k and 3.4k revs until you can hold the car at 3k for any speed.
- For driving around town, use 2nd at 25mph.
- You can keep the compression up by not coming fully off the accelerator pedal when changing gears.
Driving like that, you don't notice any problems and feels like the car is just driving itself, with very little accelerator input. The mpg remains good. However, once the engine warms up and if you do any of the below, it reduces the mpg somewhat and now triggers the engine light to come on:
- Driving the car under 2.4k revs for any more than a few minutes makes the car complain and it loses the compression. This gives very lumpy running when warmed up but not while warming up. For instance, driving it at 30mph in 3rd gear around town
- Sitting with the engine idling for more than a few minutes. This also gives very lumpy running when warmed up but not while warming up.
BTW, the engine light is: p0420 and I've managed to trigger it a few times this evening. Once it comes on, the car drives like none of the above has ever happened. (Recently all 4 O2 sensors replaced and wiring checked, ECT sensor replaced and wiring checked, coolant refresh, spark plugs new and rechecked, coils checked. No funky smells from the exhaust outside, no fumes leaking into the car and no exhaust leaks.)
So is the code related to the lack of compression in cyl. 3 or in addition to it? As I don't want to replace the engine and find the cat is fubar'd. I just want to get the whole job done and costed up once rather than in stages as I know I'll have to replace a few hoses once the engine is out too.