Hi. I am new to the forums. So first of all I have an '03 A4 1.8T. Everything stock on it except for my Eisenmann Sport Exhaust. A few days ago my check engine light came on. I checked the codes on it last night and I got two readings. One was a cylinder misfire and the other being turbo underboost. The cylinder misfire was told to be a code that was just not erased previously, so the problem must be the turbo underboost. The problem is that when the turbo is supposed to kick in the car like sputters and it doesnt take off like i am used to. All the hoses were checked to see if they were hooked up properly and they are all fitting fine. I am not sure what else to do but to bring it in to my local dealership, which I think I will do tomorrow if I dont get any help quick enough. I appreciate any help and look forward to talking to everyone. Btw I also have a 1999 BMW M3. Thanks.

 

You did not mention the trouble code but i think you got code P0299 stored in ECU memory. Common cause for your model is the Turbo By pass valve or the Recirculate valve. You need proper tool to check this problem out. A VAG scan tool to read ECU demand pressure, ECU turbo boost pressure sensor reading and actual boost pressure reading using an pressure gauge hook up to your intake manifold. These reading will help you pinpointing the problem area.

 

Yes. I forgot to put the code in there but that is the one. My dealership could not fit me in yesterday so i wam bringing in my car on Monday. Thanks for the help.

 

Cylinder misfire can be plugs or coilpack. No boost may be a result of a code that automatically puts the car into limp mode (essentially prevents normal boost to avoid exacerbating any problems).

My money is on you needing a new coilpack. I don't know what revision your car has (maybe revision L) but replace them all at once with the latest revision R. Audi will charge you a couple hundred dollars or more to replace all four of them for you and it's like a 10 minute job. Tell them you want to buy them and do it yourself. You can probably get them $5 cheaper at a VW dealership (~$35-$40) than at Audi.

 

I have replaced my plugs already. That was one of the first things I did, but what is a coilpack?

 

The coilpacks are the things you had to take out to replace your plugs. They go out somewhat frequently. Leaving your engine cover off should help keep them cooler which should make them last longer.

 

So a VW dealership will have ones for my Audi? and they will be much cheaper? And is there a way to tell wether they are bad or not?

 

I am experiencing a similar issue with the same year make model. I am hearing a ticking sound on the top of the engine. I haven't pulled codes yet to tell what the issue my be.
Have you had any luck with your issue? Plugs, Turbo, Valves, Cylinders, Coil Pack?

Thanks.

 

Since my last post I have just been running around trying to find a coil pack. I went to Napa and the guy there told me to go to a different location to get the coil pack. I also checked a Murrays and I was talking to the guy there for a good 20 mins. He said that he had a Jetta with a very similar problem. He said to change the one coilpack (the one for cylinder 1, which is the one in my case that was misfiring). He also said that I should go to VW to get my coil packs and to replace all of them because when he changed one 2 weeks later 2 more went out so he replaced all three. Then I told him about the turbo underboost. He said to check the boost controller and said that I might have to just buy a whole new turbo. I am going to go put in the new coil pack now. Does anyone know for sure which cylinder cylinder 1 is. All I know is that it is one of the end ones.

 

i had the same code p0299 and also know someone else with the same code i have an 03 a4 quatro 1.8t manual and my problem was that the turbo was dead i realized once in 3rd gear the car wouldnt pull as hard and i wasnt going as fast so i checked everyting all the hoses and everything was fine but my turbo was dead.. the other dude i mentioned that had the same problem his pipe from the intake was cracked he also had the same code..