'99 A4 1.8T Cam Chain Tensioner Failing?
 

Engine Code is AEB. Sound is always there, other than when idling, though I haven't taken the engine past 3000 rpms for fear that I could bend a valve, ect.

Observe engine noise:

http://www.youtube.com/watch?v=PZoESTsHOQU


Thanks for any assistance.

It does sound like it, is the noise def coming from the rear of the motor? When mine went it sounded like a loud clacking noise for a few seconds on startup. Although its possible that an accessory's bearing is on its way out too. couldnt see much in the vid.

Yea, sorry about the video quality, but not too much out of place. The sound is definitely coming from the back of the valve cover; it sounds almost as if the timing chain is rattling around upon acceleration, which I would attribute to lack of tension. What I'm wondering if there could be something else, like a lack of oil pressure, leading to this issue...

I do notice that the oil temp gauge never gets to operating temperature, even on hot summer days. It hovers around 190F, and never the 240-250F that it should be. Could this be my thermostatic oil control unit stuck open like a coolant thermometer would? Or do they operate differently?

you will need to pop off the valve cover and check it out, more then likely it will need replaced, ECS tuning has them for around $300 OEM audi

^+1. Really does sound like a lack of tension. Pull the valve cover off and inspect the tensioner and the chain. Thanks jschick - we have Genuine Audi for $204. Here is that part and a few other options:

http://c1552172.cdn.cloudfiles.racks...22540_x800.jpg

Pete,

Would there be any harm in going with the $100 part from MTC as opposed to the OEM? Are there any special VAG tools that I would need to complete the job?

Thanks

Honestly, ever since we introduced the MTC brand CCT, we have sold as many MTCs as we have Genuine Audi. We sell a lot of various MTC parts, and I would trust them on my vehicle. You shouldn't need any additional tools for this job. I would recommend replacing the cam chain tensioner gasket and valve cover gaskets while you've got the valve cover off:

Cam Chain Tensioner Gasket $6:

http://c1552172.cdn.cloudfiles.racks...20931_x800.jpg

Valve Cover Gasket $15:

http://c1552172.cdn.cloudfiles.racks.../1072_x800.jpg

Thanks for all the info Pete!

My oil temps never get above 200 with synthetic. With mineral, Id see about 215. The book says remove both cams for this job. Do you have any type of manual available?

My gauge is barely cracking 175, but it lists 250 as the median temp... so, strange.

I've read that you can get away with just removing the intake cam and tensioner, but don't have a manual.