Hi guys. I wonder if there's a wizard out here who could help me work out what to do.
For about a year I've had an intermittent fault on my A3. It started with the EML coming on but was driving fine. Then the light would go off again for weeks sometimes. When the light stayed on long enough to get it into the garage and checked, I got these error codes:
P0172 - fuel trim bank 1 system too rich
P301
P130.
My local garage changed sparks and coil pack, it went off for a while. Then it came back and it started noticeably misfiring, running rough especially when idling, but again, only intermittently. It would do it for one journey, or one day, or a few days, then stop for weeks. Our thinking was that this was likely an electronic problem rather than mechanical as it was so intermittent. Since then, the garage have changed the following parts:
All 4 injectors
Evap canister and valve
Airflow meter
Crank shaft position sensor
Cam shaft position sensor
Pre CAT 02 sensor
Post CAT 02 sensor
PCV Valve
It cost me a pretty penny 😕 I picked the car up, it ran great for a week. Then one day I drove it for an hour, parked an hour, restarted and it was losing revs again, misfiring etc.. and then after I've driven it for 5 minutes it runs fine again. This time the EML is staying off. My garage, also at their wits' end, told me to take it to a specialist German car garage (it's already been into Audi dealership btw who said they wanted £800 to test which injector was faulty, so we just changed all 4 for less than £800! and it wasn't even the injectors...)
There's no other symptoms that would suggest head gasket failure.
The specialist garage is saying it passed the compression test but they'll try it again when the engine is hot. If it passes again, they want to replace the timing chain, and said it's going to cost about £1500 for parts and labour.
Would it be intermittent like this if it was the timing chain? If it is the timing chain 100%, I'd go for the replacement... but how can they be certain?
Could it be the ECM?
Could it be failing fuel pump?
I just don't know how much more money I can put into resolving this, when no-one seems to be certain what the fault is, and I've spent £2k already.
It's done 82k miles btw.
Any advice much appreciated.
