New to the forum.
I bought a 2008 reg CC 3.6 4Motion a fortnight ago, full service history, 42000 miles, very tidy. Unfortunately, after a very enjoyable 150 mile blast back home from the seller with no problems, the next day a few miles into my commute the engine management light lit up, both flashing and permanently on. The car became slightly juddery and seemed to lose some power.
Called the AA who plugged in their diagnostic equipment and diagnosed random misfires on cylinders 4, 5 and 6. With a heavy heart I took the car into the local VW garage who did their more detailed diagnostics and came back and diagnosed a faulty injector for cylinder 5. £500 later (fortunately covered by the seller) with a new injector I picked up the car but within a couple of miles the same thing happened. Called out the AA again who diagnosed the same random misfire fault as previously, so took another trip to VW and explained as politely as I could manage that the fault had not been fixed at all. So they took it in for more testing and ended up, over 2 further trips replacing 5 of the 6 spark plugs. Unfortuntely this has not solved the problem either. The coils are apparently fine.
The diagnostics keep giving different readings as to which cylinder is misfiring with no apparent rhyme or reason and the dealer does not really seem to have much of a clue what is going on. They have now tried reprogramming the ECU with software uploaded to them by VW but this has not solved the problem either.
Does anyone have any idea what might be causing this? Something electrical perhaps? Getting close to my wits end now and am starting to feel pretty sour about the whole thing which is a great shame because I loved the car over the short time it was running properly.
Any suggestions gratefully received.....