964-C2

Hi.
I have the Porsche tool 9201 to adjust the tension of the timing belt and balance shaft belt. The correct tension is 2,7 +/- 0,3 (timing belt) and 3,5 +/- 0,5 (balance shaft belt).
If I adjust the tension correct when the engine/belt is cold , and later check the tension when the engine/belt is hot, the belts are much to tight (about 5,0 and 7,0)...
If I let the engine cool down, the tension gets correct again.
I guess you are supposed to check and adjust when the belts are cold, and just forget about the high values of a hot belt, right?
Thanks for any answers.

thomasmryan

Tension is set at ambient temperature which I assume is 72F.

As the motor expands, your readings will be less.

mikey_audiogeek

Thomas is correct. There is probably a spec in the workshop manual as to the allowable temperature range.

Now that you have set your belts at cold, and measured hot, I guess you now have a "hot setting" just in case you have to retension hot...

Cheers,
Mike

bmnelsc

Belt tensions are to be checked cold. Temperature around 20C (68F). Had my '91 S2 belts done at the dealer last time with a re-tension required between 3-4k kilometers. They required the car to sit there overnight or be dropped off first thing in the morning so it could sit all day and they would check it near the end of the day.

mikey_audiogeek

Just did my belts today, at 105,000km on the belts (305,000km total).

When you buy a genuine OE belt, with it you get a card that is meant to go on the passenger seat to remind the owner to bring the car back after 3-4000km.

Pretty cool.

Cheers,
Mike