Failed Carrera Tensioners

[jmshepard]

Today I had both of the updated Carrera tensioners replaced on my 80 SC. The PO had the update performed many years ago. My best estimate is that they units were about 10 years old. This work was performed in response to a change in the sound of the engine. As the RPM increased from idle, a strange rattle sound from the rear of the car would occur. The same sound was very noticeable between 2200-2800 RPM, and again as the throttle was rapidly reduced. I drove the car to the shop and the mechanic immediately diagnosed the problem with a stethoscope. He said that this was an extremely rare occurrence as the updated tens are widely considered to be bullet proof. I was lucky that this didn’t cause engine damage from a loose chain and subsequent cog slipping. I had tracked the car 2 weeks ago and I think that was when the first started noticing some odd sounds from the engine. The work was done while I waited at the shop and now everything is good in the world. Lesson learned, nothing made by man is bullet-proof.
Jim S.

[FrayAdjacent911]

Sounds like a good catch! The 2.2T engine from my coupe that will be going into Stinky has the Carrera tensioners... but who knows when they were installed?? Glad to know that they are reputed to be bullet proof, but I don't ever believe anything really IS bulletproof... I've seen bullets penetrate some really hard stuff in my time!

[Porsche Doc]

Contrary to belief Carrera tensioners are NOT bullet proof!
I have seen a bunch of failed ones.
But it is still the best upgrade for a street car. IMO
On all of our race engines we use solid ones or the SC type with the guards on them.

[Danskman]

Did he replace one, or both? The likelyhood of two tensioners failing seems pretty slim. What was the condition of the ramps?

[jmshepard]

The left side was the source of the chain noise. The right side was replaced as well as it was not providing the normal amount of resistance. I figured that as long as we had the covers off, might as well replace both of the tensioners. Ramps were still in good shape.

[WERK I]

Is it possible you could disassemble the tensioner and take pics of it? I have heard of rebuild kits for these, which is nothing more than a new seal....I have heard. Since so little oil passes through these, I wonder if it is a case of tarnish/sludge buildup causing seal/piston leakage.

[jmshepard]

Dave,
I would like to discuss rebuilding. I saved the tens and will disassemble and try to figure out the cause of the failure.
Jim S.

[WERK I]

Thanks, Jim

Dave
'85 Factory Slantnose 930