Scott526

Hi i have a 2004 A6 3ltr and the engine light has just come on it won't go off and the car still runs like there is nothing wrong with it can someone please help with this Thanks

georgeb944

Well, a CEL/MIL is an indication that something is wrong. It could be as little as a loose gas cap, or as complicated as an engine timing issue or a transmission problem.

If you just want to know, take your car to an Advanced Auto Parts, O Reilly, or Autozone, where they will put a code reader on it to determine what codes your car has recorded. Then, google each of the codes with "rosstech" for a description of the problem and a list of what it might take to fix the problems.

If you are going to keep the car for awhile and want to do the diagnosis and repairs yourself, then invest in a good code reader. Generic code readers can be as cheap as $10 to $20, but a full function code reader that can analyze all of the electronic systems on your car will be much more expensive. The Ross Tech VCDS (Ross-Tech: Home) does everything for all VAG (Volkswagen Audi Group) cars. I bought mine about 7 years ago, and it has paid for itself many times over.

Scott526

Thanks George the car still drives fine like it always has this is what makes me think and the light stays on and doesnt go on and off

Harleyguy

My A6 is also an '04. I bought it on a used car lot. It was in reasonable shape. I had to trailer it home and in the time it took to unload it, the check engine light came on and stayed on. I put it back on the trailer and took it back immediately since the dealer had a 30 day no questions asked guarantee. They replaced a bunch of dry rotted vacuum lines and all was good. About 5 days later same thing. Stopped by Autozone and the codes coming up indicated vacuum leak and secondary air pump issue. Back to the dealer and they replaced the pump and changed a few more vacuum lines. All was good again. Been good ever since and that was almost three years ago. Get it scanned to find where to start, but most likely minor unless the CEL is red.

Scott526

Thanks for that I'll look into finding the codes is your Audi an alroad mine is an S-Line

Harleyguy

No. A6 Quatro sedan. Except for actual body parts many systems cross over between sedans and the allroad model. You can usually get the codes read in about 5 minutes at Autozone and some other parts stores. Bear in mind it will be a very basic OBD II scan and you will need to search on line to get the info. The Ross-Tech would be the way to go if you are planning on having the car a while. I don't have Ross-Tech because my computers are all Apple and the two aren't compatible. I'm retired so I'm not going to run out and buy another computer just for that. Get the fault codes and start from there. Get back on this site if you get things that you don't understand. Lots of knowledgeable guys and gals on here willing to help.

Scott526

Thanks my computer is apple as well Im in New Zealand and I will buy a scanner tomorrow and get the fault codes I dont trust mechanics at all.Thanks for your help ill get back to you when all is soughted.

Scott526

Hi i ended up just taking the negative lead off the battery for a couple of minutes thinking it wasnt going to work .Well it did and now the engine light is off must have been the fuel cap .Thanks for all the help everyone Scott526