ckakka2

A few minutes after doing a quick run through first and second, I was driving around "normally" and i thought i heard some sort of "clink" noise but i'm not sure. then ther was this sound. never heard it before and the car still seems to run perfectly fine. no codes for it. any one know what the sound is? seems to be coming from the back of the engine. pretty sure its not the oil, did that a month ago with no problems since. there was a small coolant drip but that i believe was the after-run pump? possibly that or something worse?

link to youtube for the video
- mostly apparent at 0:40 and 1:30

http://www.youtube.com/watch?v=M2d0zMtABb8

Peter Badore

Very hard to tell from the video. How many miles on your S4? The right side timing chain adjuster and tensioner are always candidates for things going wrong. I think the right side chain adjuster is the last and hardest area of the 30v A4, A6 and S4 engines to receive oil during start up. I typically see the right chain adjuster failure as the most common on the 30V 2.7l and 2.8l V6 engines. If you do your own repairs I would take off the right side camshaft cover and check for damage to the chain adjuster.

ckakka2

I have 129k miles on the car. I,ll try to get a better video up. I do remember after i did an oil change that there was a noise during start up but that went away. Might have to do with what you said about the chain adjuster. Will have to take it off this weekend. Is it safe to drive the car? Am i just not getting variable valve timing with a bad cam adjuster? What kind of damage can be done to the motor?

thanks

Peter Badore

Losing the variable valve timing will set a DTC and you can live with that.
The big issue is if the timing chain that is operated by the cam adjuster breaks and "takes" the chain with it, your engine with jump timing and pistons will hit the valves with very bad, expensive consequences. The usual problem is the camshaft adjuster plastic pad breaks apart allowing the intake chain to catch and jump or break. The right side cylinder head adjuster seems to fail first probably because of its distance from the engine oil source.

Chris's S4

No offense to anyone who believes this, "The right side cylinder head adjuster seems to fail first probably because of its distance from the engine oil source"... Seriously.. come on. That doesn't make any bit of sense when the "source is literally inches in difference to the left bank. It's actually oiled by the second bearing oil source for the left bank, and the right is oiled by the third bearing oil source... "FAR"?... really? nah... Now I would agree if it's having serious issues with getting oil... sure.. but not from a 15 mile hike up hill at 90 degrees of angle.... It's because of sludge most likely. Again, guessing that it no blockage by other means.

Sludge is usually the culprit.

Also again, no offense to anyone here.. I'm just pointing out a few things.

best thing to do is have someone fire up the engine while you got one valve cover off at a time and listen to where the noise is "actually" coming from and of course shut it down the moment oil starts shooting..... Sounds like a bad/stuck valve bucket... I could be wrong. A buddy had some serious noise like valve tick right after an oil change... it went away.

Or... like what should've been mentioned long before was to get your hands on a stethoscope and listen that way.... also no oil mess do that.. figure out where that noise is coming from and then report back.

Autozone has those.. fairly cheap...

Good luck,
Chris

Peter Badore

Chris my friends shop has over 20 broken Audi V6 engines. When the chain
adjuster fails its is the right side. Just my experience with many Audis. Have you seen the 2.8l 30V V6 or 2.7l V6 biturbo break the left side chain tensioner? Also I have been told that Audi had to revise the oiling system for the right side 4.2 V8 engine to improve oil flow to the chain tensioner and cylinder head. If I had to guess I would say the right side oil passage ways clog easily or the wrong oil weight slows oil flow in cold conditions. My friends did oil flow studies awhile back and it was amazing how long oil took to flow to certain areas of the engine(not an Audi). Also Audi has had to revise the oil system a lot on the 2.8l V6 engine since its introduction in the first application--the 1992 Audi 100 which I also owned. 8-20-11 just saw a left side bank 2 camshaft adjuster failure on 2.8l 30V Passat with lots of miles on it. The plastic pads on the adjuster feet can crack and fall off.

ckakka2

Car ended up stalling out and wouldn't start up after. Cranking but no start. After a little bit of research turns out the crankshaft position sensor was throwing a code (never had it before, had a MAF code). Reached down there...PITA. Took it out, only half of it came out...wtf. Took about a day to fish the other half out. Put in a new sensor and boy, the car screams now. Runs better than ever before. No more MAF code either. Thanks for the help.

ckakka2

Noise is gone as well, maybe it was just bad timing.