I have a 2004 A4 1.8T. Just turned 65k....I bought it with 45k on it almost 2 years ago.

Since I bought it I have changed my oil at 5k, religiously.

In the past few months the engine light has been coming on..it idled rough. I had the coild and plugs changed, new air filter etc....it ran great.

Now the car is idling rough again, it's eating oil and the engine light blinks. it's also making a knocking sound when idling. While driving...it's fine.

WTF? The dealer says it may be sludge. Which is covered under the warranty.

Any ideas out there?

 

I went through the same thing a few months ago. The oil pick up tube will plug if you use regular oil. (Non-synthetic). This starves to top of the engine for oil and boom failure.

I thought I was totally screwed, but Audi fixed the car and picked up the tab. You will need all of your receipts for oil changes, (mine were almost all at the dealer so it was easy), but they will cover the car for up to eight years. Search sludge issue on the forum, I even found the original letter Audi sent to owners about the issue. Audi recommeded the wrong oil for the cars so they will fix it. My dealer was kind of bitchy at first but I told them I would contact AUDI USA for a customer advocate they completely backed down. (I read that somewhere on here too) it totally saved me from replacing my engine.

Good luck!