Cam chain tensioner failure 86 3.2

[Sophie]

I was very fortunate to have heard a loose chain when pulling into my garage. After removing the covers the RH chain was loose but still in time. Tensioner pushed in and out easily. After removing and clamping in a vice it started to have normal tension. Question. Obviously the tensioner had failed while in the car and it really destroys my confidence at this point just to replace them.The car is my daily driver and is very well maintained . Oil level good and oil pressure good. 200K miles.

[RSTarga]

go with the oil fed tensionors. you were lucky the valves didn't hit the pistons

[gregwils]

You can always use the mechanical stops to prevent complete failure.

Jerry Woods Chain Tensioner Mod

[JR911]

Sophie, Can you describe what a loose chain sounds, just for future reference.

Thanks!

[Sophie]

To JR 911 The sound is much like a bicycle with a loose chain . They are about the same chain size and have tensioners in most cases. To RS Targa The 86 carrera already has oil fed tensioners. To Greg Wils Thanks for everyones reply but the Hydrastop you suggest is only fot the early tensioner through 83. The later oil fed has a shaft that is smaller at the top and larger at the base. My search is still for someone that has seen one of these fail and why it would start to work well when bench tested. Thanks again.

[Flieger]

Years ago, there was a batch of defective Carrera tensioners.

More common is a little stiction that needs "exercising" when priming.

The "Jerry Woods Mod" can be done to perform the same function as a stop collar. You disassemble the tensioner and insert a piece of rod as a spacer behind the piston. It is only long enough so that is can compress enough to get the tensioner mounted and to have an oil pressure cushion as the main force on the chain. It is not short enough, however, that the piston can compress fully to the point the chain falls.

This does not mean you should not keep an ear out for tensioner failure. Loose chains are bad and can come off.

Also, a tired tensioner is noisy at idle and as revs climb, higher oil pressure makes the piston more forceful at tensioning and the noise gets better.

[KTL]

A similar pressure-fed tensioner modification like that which Flieger refers to can be found here in SmartRacing's catalog on page 26 (page 2 of the link below)

Smart Racing Carrera tensioner modification guard

And the instructions for modifying the tensioners with the Smart Racing kit are found here

Smart Racing Carrera tensioner guard installation procedure

[Sophie]

Thank you very much Max. The noises to listen for should be a great help and confidence builder after installing new ones today. As a car driven two hours every day anything changing is always noticed and a change in idle sound will definitely be noticed if it is there. Thank you again.

[Sophie]

Kevin Thanks for your infomation. I looked at the setup procedure and have saved part numbers and contact information. BUT. It is amost all back together so regroup for the next time in . Thanks for your help.

[Scott R]

Those safety collars, the first ones linked are not a great idea. When my tensioner let lose the chain cut through the collar like warm butter. It ended up in so many pieces in my oil sump.

[kodioneill]

Originally Posted by Sophie

I was very fortunate to have heard a loose chain when pulling into my garage. After removing the covers the RH chain was loose but still in time. Tensioner pushed in and out easily. After removing and clamping in a vice it started to have normal tension. Question. Obviously the tensioner had failed while in the car and it really destroys my confidence at this point just to replace them.The car is my daily driver and is very well maintained . Oil level good and oil pressure good. 200K miles.

i'm in the middle of a engine rebuild and while i was bleeding the two brand new tensioners one of them failed!