Engine-Man-Light baffled my mechanic

[zeratul]

Hi. I've had some trouble sorting this problem for the last 4 weeks. A4 1.8T Cab.

The Engine Management Light came one one day coming home, it still drove the same tho, but called the RAC and within 10 mins, arrived and said it was a sensor that controls the fuel mixture as it was reading that it was running lean ( along with another fault code, which he thought would be a knockon effect from the 1st code ).

The garage changed the sensor but the second code still showed so after looking into it, said the Cam needed changing to get to replace this part. After this was done (a second time as the 1st time he'd fitted it a tooth out!), I had it back and all was well until the EML came on again and was now struggling to get up decent speed and was not ticking over correctly.

So he's still got it and its still showing that its running lean on the mixture and runs ok initially but then starts to misfire later in the day when its run in a bit.

Its an independent BMW specialist, he has Vag Com, he's still having trouble finding out the problem.

I've not got the fault codes I'm afraid but does this sound familiar to anyone? He's had it some time and will have to collect it and take it to Audi next week and pay them also!

[arman123]

get the airflow meter checked or could be going into limp mode check the turbo boost vavle or n75 valve maybe thats a bit lazy but do a vag diognostic check first so you know wat wrong wat ever code you get search them in google and you will know wat wrong

[zeratul]

I collected the car today and he said it still has the same faults. He thought it was sorted as after trying swapping around the fuel injectors it was working fine - but then the fault reappeared when driven in the afternoon.

So he suspects now that it may be a dodgy electrical connection.

He said he has changed the lambda sensor only so far. I told him about the MAF.

The fault codes that come back is always: 17544 (fuel trim - which is the original fault it went in for before he changed the lambda sensor some seal by the head which also meant cahnging the Cam Belt).

AND... in addition - code 16684 (random misfire) & sometimes along with 16687 (Cyl 3) and occasionally 16688 (Cyl 4) but not so much!

But it runs fine, not like when a coil has gone, but kind of half firing. He's checked Cyl compressions and they're all equally fine.

Anybody any ideas? Is the MAF still a possibility?

In addition! with just the ignition on, I heard a clicking sound comng from behind the drivers side headlight - when i wiggled the wire it occasionally stopped until it finally did and couldn't get it to come back! I'd not heard it before but can't see anything that could be behind there and think it is just a coincidence.

[arman123]

get you maff checked unplug in and drive see if any diffrence could be you ignition control module get that checked or change it for a aftermarket one

[zeratul]

Do you think its safe to drive it to wok and back ( carefully, 10miles to and from ) this week until the mechanic can look at it next week?

[arman123]

dont know why it shouldnt be but take the maf conecter off and give it a blast up and down the road see if any diffrence if not then dont know mate could be your ignition system and to be honest dont really know much

[zeratul]

As an update - the solution may have been found by Audi.

A couple of weeks ago my garage had another go and changed the MAF for a new one. Seemed to be fine and after he tested it a couple of days presumed mended. Got the bill for all the work carried out and agreed to pay 3 lumps of £250 over 3 months (£748)!

So last friday the Engine light came back on! Called, and told garage I'm taking it to Audi and will see what they say - then look at his bill then. (In all fairness he's spent some time on it)

Audi came and collected my car http://www.audi-sport.net/vb/images/smilies/biggrin.gif with a diagnosis and
a replacement 'breather valve' - they bring it back to me and it seems to be driving fine so far http://www.audi-sport.net/vb/images/smilies/biggrin.gif £82.

What are your thoughts about what to do about my bill with my garage?

[Audi.Boy]

Glad to hear your car is running fine again, so many interesting problems on here...