mkongsiri

Yes, I replaced the passengers side upper tensioner and the noise was gone. Each of the upper upper tensioners has a hydraulic piston that tensions the chain. I decide to replace the drivers side for good measure and am almost done. I have to say the hydraulic piston in the tensioner appears to be the achilles heel of the assembly as everything else looks in good order. I've seen alot of posts saying the the only sensible course is a complete engine pull and replacement of all timing chains, tensioners, etc. I say it's complete Bull$#%t.

johns12

I'm looking forward to seeing the photos and video. Thanks for taking the time.

Luis A.

I just found this TSB indicating the sound is normal for 1-2 seconds upon startup. What do you make of it?

http://uberlame.com/a6_tsb/Engine/Ra...ne%20start.pdf

mkongsiri

Yes, oil pressure has to build on cold-start for the tensioner piston to apply pressure on the chain. There's also some noise associated with the injectors. My 3.2 with 100k miles on it displayed the cold start symptoms and it did go away after a few min. But driving home one day, it made a very loud persistent clacking sound. Sounded like an old diesel rabbbit. I took a video of the engine running, you can definitely hear it while it was running at normal temps. I initially thought I might had a failed connecting rod. But when I got the car home and listened, I decided that a sudden failure like that was most likely the chain tensioner as it was loudest on the passengers side. I definitely did not drive the vehicle after that as you can easily throw the chain off timing and ruin the valves. I cringe when I see people revving the engine in hopes that the sound will simply go away. I wonder if the initial cold start sounds are a symptoms of the seals inside the tensioner piston wearing out and needing more time to fully extend. Ill film a cold start with the new tensioners installed so you can compare with your car.

jujuC6

Right on.

jujuC6

This sounds like the beginning of the end. Try to figure out which one of the four it is and act on it, don't wait until it gets worse. Wished I had known what it was for sure from the start when it happened to me.

mkongsiri

There is a small lower tensioner, and if that fails then you are out of luck, the engine has to come out. As I said initially, im prepared to do it if needed but it was not. I bought the entire engine timing tool set for $150 new off of ebay, as well as crank turning tool ($20) and 12point 14mm camshaft socket ($9).

jujuC6

Nice, good luck with this. Most likely it is the upper ones as they are the more common. Here is my post on this when I did not know what the heck was going on.

https://www.audiworld.com/forums/sho....php?t=2809217

mkongsiri

Thanks. I finished tensioner installation already, and the engine runs beautifully. 4 hours total. I just have to put the bumper back on tomorrow as I also repaired a bad adaptive headlight and replaced serpentine belt and tensioner.

jujuC6

Great job, nice to hear it all went well. Now that u mentioned S.Belt and tensioner, I have the parts and still have not done it at 144k. Maybe I will get on it this weekend.