2014 Q7 3.0T Upper chain tensioners at 80k miles

[dimab]

As many other 3.0T Audi engines mine was sometimes suffering from 2-3 seconds upper chain rattle at cold start. The rattle was coming from the driver's side tensioner. There were no codes and the engine was running great.

Audi states in a TSB such rattle is normal. I don't necessarily agree with that, because rattling chain banging on brittle plastic guides may eventually break them.
Below are some pictures of what I found upon upper chain cover removal. Broken top guide with the piece stuck down below the drive chain guide bolt:







Broken tab on the tensioner guide (new and old tensioners):



If anyone is doing this job for the first time, PCV hoses can be safely detached from valve covers using a piece of credit card wrapped around as a collar and pushed into the hose opening. There is expandable locking ring inside the hose holding it in place:

[maximusBH]

Thanks a lot for this update! I have the same issue at 85K miles. I've read a lot about it and for many owners this rattle will not provoke any damage but... it's really annoying to start a working day with this sound at cold start!



Envoyé de mon SM-G955F en utilisant Tapatalk

[dimab]

A quick update after 11 months and 7.5k miles: no chain rattle on startup so far.

[G-Can]

A quick update after 11 months and 7.5k miles: no chain rattle on startup so far.

a question, is it neccesary to remove valve covers and secure camshafts, if we are replacing only two top tensioners?

[dimab]

Yes, you will need to remove the valve covers and secure the camshafts to remove camshaft sprocket from the exhaust side and camshaft adjuster from the inlet side. Then you will be able to access top timing chain tensioner bolts.
I highly recommend using a quality triple-square bit to remove the camshaft bolts, as they are torqued quite tightly (assuming they haven’t been removed before).

[G-Can]

Yes, you will need to remove the valve covers and secure the camshafts to remove camshaft sprocket from the exhaust side and camshaft adjuster from the inlet side. Then you will be able to access top timing chain tensioner bolts.
I highly recommend using a quality triple-square bit to remove the camshaft bolts, as they are torqued quite tightly (assuming they haven’t been removed before).

so what can be replaced this way? just a tensioner per side? OR a chaing can be replaced as well? Im buying parts and want to make sure I dont but extra stuff, or miss on something.

I have to do valve cover gaskets and oil filter housing gasket, so while its open then I would have them replace upper tensioners, and while there, might as well remove supercharger to make things easier to acess timing, and while at it replace PCV and waterpump/thermostat, and while at it carbon clean

started from buying 3 gaskets to a full big service.... damnit

[dimab]

Upper tensioners only, one per side. Replacing any of the timing chains require engine removal.
Also, it's much easier to replace the oil filter housing gasket with supercharger and intake manifolds removed.

[G-Can]

Upper tensioners only, one per side. Replacing any of the timing chains require engine removal.
Also, it's much easier to replace the oil filter housing gasket with supercharger and intake manifolds removed.

thank you!
yes, so thats what got me into rabbit hole. I want to make my mechanics work easier, it would be easier for him, and for me Id have everything done at once.

I have some rattle/clicking when starting, and even when its warm there some sort of more like clicking then rattle, so I;m assuming its the chains or whatever, so hoping that will sort it out. Otherwise I have zero codes on the car and it runs great, but its spitting oil on every single gasket there is