I have a 2002 Audi A4 1.8T with 129k miles and lately I have been hearing a loud engine knocking whenever the engine is at low RPMs. I start to notice the issue after I have driven for about 5 minutes. It does not start right away after the car has been off for an extended (at least 4 hours) period of time. The noise sounds like it is coming from the upper engine and it sounds like there is metal hitting metal. I have been using 10W-50 oil because my mechanic suggested that since the oil I had been using kept burning up, that I should move to a thicker oil.

This morning, I took it to the mechanic and he assumed that the oil was not reaching the top of each shaft, and thus was not getting enough pressure. We switched to 10W-30 Synthetic and the problem did not go away. My mechanic does not work on Audi's normally but he has done simpler things such as oil changes and changing belts and whatnot. He does not know what this problem is and figured that I should investigate before he takes apart the motor.

Does anyone have any ideas what this may be? I am nervous that I may be doing permanent damage to the motor, so when I do drive it, I make sure I keep the engine revved at above 2000 RPMs to stop the noise and presumably keep the wear down to a minimum.

 

have him check the oil pressure and also put some engine oil system cleaner in there see if that does any good

 

get it to someone who knows about audi's/ VW's because his guess as to what is wrong with it is probly as good as yours. metal hitting metal sound is never good bro! what gas have you been using?

 

Sounds kinda like a bad camshaft adjuster.