Hello all,

History first. Just bought a used 2004 A4 two weeks ago (1.8T FWD with CVT) with 60K miles and I have been veryhappy with the car. It had all the scheduled maintenance performed. I had the oil changed with Castrol Synthetic 5W30 2 weeks ago and it has driven fine, buta week laterthe oil pressure warning light starting coming on when I am decelerating or coasting in the 1,800 - 2,400 RPM range. If I start to accelerate again or drop the RPMs below 1,200, the light goes off.

Took the car to a certified Audi mechanic, which took the pan off and found only a little slude on the pickup tube screen -- not enough to cause the pressure drop. However, we replaced the pickup tube and the oil pump just to be safe, put it back together, but still the same problem.

The mechanic thinks I have a vacum leak from some tube on the back of the crankshaft. Having never worked on an Audi, I don't know if that makes sense or not, but it doesn't seem to add up. Is this possible?

Thanks.

 

doesnt sound like it.

is the light only coming on at decelleration?
do you have a check engine light on? even if you dont. i would still have the car scanned for codes....
autozone does it for free i think?

 

http://en.allexperts.com/q/Audi-Repa...sure-light.htm

maybe?

 

pretty vague response in the URL.
but possibly

 

Alrighty, here is the latest. Oil pressure was 0psi at a hot idle. Tech found very little sludge in the pan or on the head, but changed the pickup tube and oil pump. After that, hot idle oil pressure was up to 12psi, but still under the 18psi idle spec.

However, the tech started looking through the service manual that recommended that he check the oil breather vacum tube that goes from the top of the engine, down the back, and connects to the oil filter housing. Apparently the vacum in this tube influences or controls an oil pressure bleed valve in that housing. The tech found my tube to be in very poor condition and not holding any vacum. After replacing the $90 tube, my hot idle pressure was up to 22psi, so all is well. Who would have though!

Thank you all for your suggestions and help.

 

that is exactly what was wrong with my car! But i didnt bring mine to audi, i brought it to my mechanic, he found that a oil tube had completly disenigrated(sp?) and was leaking into a vacum hose that had a hole causing low oil pressure, a vacum leak, the engine to run lean, and misfire...etc. He just ordered the parts for me should hear back today!