'88 924S Clutch Slipping when Overheating

[mdmccull]

On a hot day (85?+) and sitting in traffic my temp gauge starts to rise.
From 1st to 3rd gear when my low-end torque is greater the clutch will slip. Once the car is moving and the engine cools down the clutch grabs just fine. If I stop then drive again before the engine has time to get really hot I'll have plenty of grab on the clutch and it will not slip. On cooler days I have no slippage.
Also I can sit on an incline and keep the car stationary with the clutch without slipping.

I have two theories. One the clutch disk is worn and glazed. When the engine gets hot due to expansion I have more slippage. Maybe the clutch is continually slipping providing excessive heat.
Or I have something wrong with the cooling system, bad water pump or timing belt making the engine hard to cool itself on hot days overheating clutch, which might cause it to slip.

I'm open to suggestions.

Thanks,
Mark

1988 924S
108K

[toolboy62]

Is it possible the engine is getting so hot that pressure is building up in the clutch slave cylinder and partially applying the throwout bearing?

nate

[Britwrench]

Define "overheatiing"

Are the cooling fans working?

If the clutch slips, you need a new one.

The overheating problem, if there is one, needs fixing too.

[nynor]

my '83 was doing this at the end, right before i traded it for the turbo (which i regret). turned out that the clutch fork was bent, throw out bearing was bad, and the clutch disk was worn (not worn out, quite yet, just worn). these things combined caused similar issues. i noticed it was worse after my wife drove it (she has a different clutch style )