My A4 1.8T 2001 AVJ engine makes a hard burred sound while driving slow around 1100-1800rpm (happens higher up but it is most noisy at these rpms), it happens most of the times when you let the foot of the gas and then press it again. It comes from the engine and I can hear it inside the car. Sometimes, the car also sounds like an diesel and has a knocking/ticking sound coming from the back of the engine where the chain adjuster is. I cannot force the burred sound on idle or when reving her up, only in gear and when the car is 90 degress warm.

I'm going to take the valve cover off next week, how do I check the adjuster for wear?
I've read about disconnecting the solenoid and see if there is a change in sound but as said before my car does not always sound like an diesel. Most of the times it sound ok. But I can force this sound by pressing the clutch the same moment the burr sound appears, then the enginge ticks on idle.

Is there any DIY writeup for changing this part? Edit: found it here:
http://www.ca-va.org/tech/camtensioner/index.html



Many thanks.

 

I have an AWM motor with a very similar problem. I am not convinced it is oil pressure since it happens at a specific temperature with both10-30 or and or 10-40 oil. It can be a contributor but not 100% convinced. Additionally is only occurs hot at 750-800 rpm. Goes off at 900-1050 rpm.

My noise is not consistent and comes and goes. I have cleaned my motor with Sea Foam and have done a visual inspection of the pickup through the oil sensor in the pan. All clean.

I have also removed the valve cover and really saw no issue, but at that time I was not sure what I was looking for.

I know it is the cam tensionerbecause the solenoid actuates the tensioner.I found the solenoid is only actuated whenthe turbo kicks in. As a test I used a connector and and applied12vdc to the solenoid and actuated the tensioner. Magicly the noise disappeared,but the idle went rough given the intake cam advanced. Remove power and the noise is back.

I found the hard way if you remove the solenoidand start the motor the plunger will blow out with along stream of oil. Thus I know we have oil to the top end.

Now what I suspect is the following: 1. If the tensioner is spring driven without any oil actuacted with oil. Thus at idle the spring is weak, the chain has stretched or the guides are worn.

Iall have read that folks report that after a short time they continue to have issues after replacing the tensioner. Leaving me in the camp of astretched/warn chain.

That is my 2 cents. If you can keep me posted on your progress that would be great.

 

Just came back from a testdrive. I can now confirm that the sound only occurs when I play on and off with the accelerator.
I tested to drive constantly at 1400rpm sharp in 1st gear on a straight road - no burred sounds at all. But if I let off the accelerator and then on it again just for a second the noise came back, also if I accelerated up from 1400rpm with the trottle just a couple of 100 rpm.
1400 rpm was not a magic number, it happens at both 1100 and 1800rpm aswell.

Quote:

Iall have read that folks report that after a short time they continue to have issues after replacing the tensioner. Leaving me in the camp of astretched/warn chain.

Where have you read this?
If think I'm going to replace the adjuster I will also change the chain, it doesn't cost much more.


I have also found answer to my second question in the first post. Here is a complete guide on how to change the adjuster:
http://www.ca-va.org/tech/camtensioner/index.html

 

If you do replace yours, can I obtain your old one? I will pay for shipping. I want todisassemble this thing and post a full article on the theory of operation, detailed break down and I want to determine exactly what is going wrong with these items. This appears to be a common problem but am not comfortable with the information I am getting. Everything is subjective not scientific.

Thanks

 

If you read that article, they don't say it solves the problem 100%..

 

You can't check the tensioner for wear, if your hearing it at different times and not all the time, you more than likely have an oil pressure problem not a tensioner problem.
First thing is to check your oil pressure, un-less you wanna buy a $500 tensioner?