Greetings... so, I posted a thread regarding my maintenance hat trick of water pump, thermostat, and alternator cable.


As soon as I received my OEM thermostat w/ housing, it went on the cooktop and boiled it till it started opening. it is specked as a 83c stat (181f)/// but it started opening at 184, and fully opening at 188/9.


after replacing my original OEM stat... I decided to boil that one as well, and it seemed to start opening at 189F, and fully open at 202F.... quite a bit more than the prescribed 181F temp.


so... question is this... does the stat spring weaken a bit from cycling over the years/miles, or do some open later than others?


my 08 has 41.5k on it, and it was very easy to compress the stat spring with my hands on the oem unit with 40k plus miles on it.... while the new in box oem unit was near impossible to compress even a 1/16th of an inch.


pelican suggests Porsche stats/gauges don't report accurate readings from their stats/gauges, and that the gauges read low. per my findings, I would beg to differ,suggesting that the oem stats read correctly...not the 20+ degrees over the suggested temp opening... thanks for your thoughts,...


PB.

 

Yes, metal or anything will lose its shape/memory over time and after many cycles.

Bote, your oven-test will be different since when installed, there will be fluid pressure from the pump against the thermostat. The pressure might open the coil a little bit more. Besides, the extra 3degrees might just be manufacturing tolerances. --- IMO

For references, I have worked on many parts (especially on the '83 SC) that are coil/valve driven that, after many miles of use, I had to open them up so that the clearances/positions are back to factory specs.

 

Thanks for the thoughts Cab... Before installing the new OEM housing/stat, I first and foremost wanted to know the stat I was installing was functional as I certainly don't want to have to install it again, re-air lift the cooling system,etc, even though the stat/housing is very easy to get to.


Just trying to compress the new stat was a chore to even get it to move 1/16", versus being able to fully compress the old unit @ 41.5K miles with the palm of my hand. There was no room for me in not doing a new stat while I was already in there installing the new water pump, which was worth it and didn't take too much time and the original unit did have some play in the bearing....~1/32nd " or so...not much, but a wee bit.