Engine thermostat to replace ?
 

Hello pelicanite,

I am rebuilding my 1982 SC euro engine due to a broken piston. The engine is stripped out and I am checking and mesuring all the parts at the moment.
I checked the engine thermostat, I put it in boiling water and just before the water starts boiling the thermostat started to open the hole going to the radiator. So that's good, it fully open when it is warm. My problem is when it is cold... the hole going to the radiator is never fully closed, see the picture :

http://img164.exs.cx/img164/1963/thermo1cm.jpg

There is small gap. I don't think it is very important because the other hole is fully openned so the oil going to the radiator is very little. I would like your opinions, it is normal ? Do I have to replace it ?

Thanks

Gilles

You can check it by heating it in an oil bath and observing the temp at which it opens. Remove it and allow it to air cool and you can watch it close.I my experience these are very robust items and usually don't fail. They also aren't terribly expensive new, so you can always take the safe route if you're not up to testing it.

I think a little gap is normal to allow some oil to seep into the cooler.

Hint: Make sure you install the thermostat the correct way. Line up the openings in the case with the openings on teh thermostat.

AFJuvat

The t-stat mounting studs are slightly off-set so it can only go in one way. Porsche is pretty smart, sometimes.

Thanks for your replies. I think I am going to replace it.


Gilles

Is it really worth the $80 for that small gap that maybe there by design from the factory? That looks to be a replacement thermostat, the superceded 964 part. That's what I got when I had to replace my thermostat.

The gap is there by design, there is no need to replace it. Some oil has to seep by and enter the cooler to bring it up to temperature. That way, when the t-stat opens fully, the shock of hot oil entering an otherwise cold cooler doesn't rupture the cooler.

Your money is better spent elsewhere.