Hello-

I have an audi 2001 a4 1.8t. The motor has 82K on it. The timing belt, water pump and tb tensioner were replace about 500miles ago.

For the past 3-5K miles I am having a diesel noise at idle when the oil is at temperature. It is coming from the top end back of the motor. When the motor is warming the motor sounds fine. On an initial startup you will get the 1 sec tap then the sound is gone once the lifters pump.

The car runs fine and the noise is gone once the rpms are at 900 verse idle at bout 750.

I suspected the cam chain tensioner but when I pulled the valve cover off it appeared fine. Unless I don’t know what I am looking for. Can anyone detail specifically what one needs to check to see if the tenionser is bad?

Currently the tensioner guilds looks fine and the chain is taut. I can move the chain slightly on the sprockets. In general it appears fine. Nothing is loose lifters and cam all flush fitting. No loose lifters. Very little sludge or practically not sludge. Gave it a clean then reassembled.

My next attack is to flush the motor and blow out the oil pan. My thought is maybe the oil pressure is too low at 750rmp? Can the pump be going? I think I am running 5-30 oil. Should I try 5-40?

I see many posting on this subject but no definitive solution.

Your input is much appreciated?
Thanks

 

i am currently having the same issue with my 2003. my tensioner appears to be taught as well. you might need to replace the oil pick up tube. thats what im doing ( car is in the shop ) the ones on the 1.8t clog super easy. so it restricts your oil flow into yor top end. i will let you know how it works out but it appears thats what it is. did you check your oil pressure

 

lifters get very loud on the 1.8t's... especially if you let it idle for a bit or dont let the car cool off before turning it off. To get around this i change the oil right on time always and use mobil 1 (0-40 for a little bit thicker viscosity)