cam chain tensioner pad wear

[RS6 rick]

What test is done to check for pad wear and what should the readings be ? Have searched but can't seem to find the actual name. Thanks for any and all help. Be safe.

[Aronis]

New Old

The "cam phase" will tell you some information as the spec is -3 to plus 6 degrees at idle. Too bad there is not a CEL triggered when it's out of spec. The only way to know for sure is to pull the valve cover gasket off and directly look at the pads. You cannot see the bottom pads unless you remove the chain tensioner.

If your car is approaching 100k miles you should consider just replacing them. The plastic shoes can be replaced and actually come in a complete cam seal kit with everything you need to replace the shoes (but you'll also need 52 new bolts for the cam mounts).

Mike

[RS6 rick]

New Old

The "cam phase" will tell you some information as the spec is -3 to plus 6 degrees at idle. Too bad there is not a CEL triggered when it's out of spec. The only way to know for sure is to pull the valve cover gasket off and directly look at the pads. You cannot see the bottom pads unless you remove the chain tensioner.

If your car is approaching 100k miles you should consider just replacing them. The plastic shoes can be replaced and actually come in a complete cam seal kit with everything you need to replace the shoes (but you'll also need 52 new bolts for the cam mounts).

Mike

Thank U !!

[hahnmgh63]

Also to add to what Aronis said, these cars are starting to get old and the plastic in the tensioners gets brittle with age as well as heat so even though there is material left in the pads there have been instances where the pads crack/break and then you have the metal shoe against the metal chain. This is starting to occur in more and more cars, Audi's, Porsche's, BMW's, etc... as they all seem to use similar systems and/or plastic chain guides.

[DHall1]

Hopefully those of us that pop hoods and place fans after parking will have longer term cycles of these parts.

Its no accident the pass side rear always seem to fail first. Guess what it's close to?

Knock on wood....I have never needed them.

[lswing]

About 20 pages on this...https://www.google.com/search?q=site...+cam+tensioner

Use "site:rs6.com cam tensioner" or similar to search the site. You can monitor numbers as mentioned through VCDS. Mine also gave a signal with clicking noise on startup, got worse from 95k-100k miles, then total failure.

[Aronis]

Sorry I did not take any photos. My mechanic is currently working on an M5 (2003 or so) V8 and is replacing the seals on the Vanos controllers. BMW uses a much more durable set up for the Cam Phase adjustment. It's all metal. There are some plastic guides also but they are much bigger and broader than the tiny ones on the Audi cam tensioners. If you look at the setup in the new V8 (4.0 liter) they use larger pads on the cam tensioners, but still the similar type.

BMW uses a concentric gear on a spline and moves the gear in and out on the spline to vary the cam phase. They have a series of seals that can go, a nylon seal which was interesting, BUT you can buy a kit for $20 to rebuild the unit. Those VANOS things are $3500 each so much more than the $800 for our cam tensioners. I should have taken more photos of the BMW. I am pretty sure there was at least one set of internal plastic guides but I may be wrong. I'll swing up on Monday and take a look, I doubt he is finished with it.

Mike