[Audi A3/S3] Help! - A3 chronic misfire

[Raspeir]

Hey All,

I’m coming here very much cap-in-hand to ask for advice. I’m at my wits end to tell the truth. I can fix computers, I can fix cameras… but cars are new territory for me. This is a bit of a long one, but it’s been a bit of a saga so I figure it’s best to tell all..

Two months ago I bought a 2001 A3 1.6 from an auction. At very first it seemed to be running okay, though we had noticed the EMS light was on. On the drive home it started getting pretty lumpy, to the point where it was misfiring constantly. The problem started initially to only show up when the car was hot (when it was cold it was fine)

I took it to an electrical and injection specialists due to the EMS light. They ran some tests and found that the compression was down on cylinder 1, and that there was an air leak around the injectors, there was also a constant misfire on the cylinder. They thought it was a mechanical fault and thought the head gasket might be suspect.

Took it to a mechanic to get the head-gasket taken off and replaced, and the pistons looked at, but he was convinced it was something else. He did some more tests, opened the engine up and replaced:

The injector seals (which were damaged)

A cracked inlet manifold

The ignition coil

The engine was still missing. However he claims he managed to get the falt to move from number 1 to number 4 by swapping injectors over. He then says that he swapped the injectors between 3 and 4 to confirm this, however the problem remained on number 4.

After this I decided to bite the bullet and take it to Audi. Their report also started that the problem was now on number 4 cylinder. They believed it was an ignition problem and replaced:

The breather cap,

The crank case breather pipe,

The oil separator

Gave it new oil and filter

One new spark plug

They then returned it to me saying it was okay. After 300 yards even I could tell it blatantly wasn’t. The EMS came back on and the misfire was still present, though less constant than before. I took it straight back and they performed the same tests. They then stated that it was misfiring on number1:

This time they replaced:

HT Leads

Spark Plugs

I drove it away. It was gorgeous, purred like a kitten and flew around like nobodies business… for abut 30 miles. Then same problem. Idling in traffic and it started to misfire again, got gradually worse to the point where I was worrying if it was going to make it home. Next morning I started it up to take it back to the garage and it sounded absolutely fine again. However the problem re-arose much more quickly and after about 20 miles was again ever present. Misfire on number 1.

They took it back in, changed one spark plug and returned it. I wasn’t convinced it was right from the off, and was proven right when the problem arose again after a day or so.

Audi had it a 4th time. Said the same thing again and this time:

Cleaned the plugs

Replaced a couple of torn seals (I think on the valves or the inlet manifold)

Cleaned the injector valves and swapped the ones on one and 4 (they haven’t done this before)

This time it drove okay. They had kept it overnight and got the quality control manager to do 100miles in it (to his home and back) to see how it fared. It made it there and back fine. I picked it up and within 10 miles it had gone again. Audi took it back and said they can’t do anymore without asking for £1000 worth of permission for a strip down. No chance!

To add to my worries, the bearings have gone in one wheel. so now I can’t even hear the engine!

If anyone has any ideas/advice/suggestions, I’d be incredibly grateful to hear them… After around 8 trips to various garages and hundreds and hundreds of pounds I’m willing to try whatever it takes.

Possible theories at the moment are:

Sticky Piston Ring

Sticking injector valve.

MAF sensor

EMS system (though audi have said electrics are fine)

Personal observations:

I swear I keep hearing a gurgling noise from the engine, like water moving. Though I’m not sure if this is just me imagining things.

From what I’ve read about/searched up, it sounds like a lot of people have had similar problems caused by a MAF sensor. Is it worth me giving it a try changing this?

Thanks hugely in advance for any advice

Adam

[whoopee]

sounds more complicated thatn just the MAF. however you could try the following:

unplug MAF sensor located after air box, engine then may run more smoothly indicating a faulty MAF. you will get a yellow engine managment light but this will go away when you plug the sensor back in and drive a few miles then restart engine. if the sensor is faulty then you can clean them with meths or contact cleaner but be careful not to poke them or leave resuidue on the sensors.

having said all of this i'm not sure if the above just applies to turbo engines..... but good luck

you can also log your MAF readings such as max air flow etc there is a thread discussing this for S3 1.8T somewhere.

[Jamiekip]

It does sound like the MAF symptom or coil packs???

I can't believe they ahven't checked the MAF yet though... it's such a common problem. Have they mentioned it to you at all?

If it does turn out to be the MAF i'd be pretty upset with the Audi garage in question. Looks like they have done a lot of work for you (and I'm guessing at some cost to yourself). Let us know how you get on!