Oil thermostat rebuild / set

[Wyvern]

Hello .
I have searched and read about the oil thermostat.

I have a 75 911 s, 2.7 with the oil thermostat for the front cooler in the pass side wheel well.

I want to check/ rebuild / adjust the thermostat.
any links, info, input would be very much appreciated

I am running a bit hot and think it may be set wrong or not fully opening.

[Wyvern]

no one ... ?
I will take it apart and figure it out this weekend.
Seems like I may need to photograph and do a "how to"

[fintstone]

A good search will get you there every time. These links are likely what you need

oil thermostat (wheel well) failure

Thermostatic oil plunger end-plug removal...?

External Thermostat Repair In Situ?

[Wyvern]

Thank you "Fred"

[fintstone]

No charge. Feel free to ask if you get stuck. If you learn anything new about this...pass it on. Thermostats are one of the greatest mysteries of the universe....right up there with turn signal problems. Good luck.

[boyt911sc]

Originally Posted by Wyvern

Hello .
I have searched and read about the oil thermostat.

I have a 75 911 s, 2.7 with the oil thermostat for the front cooler in the pass side wheel well.

I want to check/ rebuild / adjust the thermostat.
any links, info, input would be very much appreciated

I am running a bit hot and think it may be set wrong or not fully opening.

Brian,

The most difficult part is removing the auxiliary thermostat from the hard lines. Once you're able to remove the thermostat from the car, you could do the physical inspection. Clean the thermostat very well before you disassemble it.

Place the auxiliary thermostat in warm water and heat up the water bath. You can do the test without a thermometer. Water will start to boil at 212°F (@ sea level). The auxiliary thermostat is set to open around @ 186°F (call this temp. as 180 plus).

The plunger will start to slide open @ 180 plus and should be partially open before the water starts to boil violently. If the slide valve does not open freely before the boiling point of water, the plunger/spring mechanism should be corrected.



This type of thermostat is not adjustable where you could adjust and set it the valve opening. Please take note of the two (2) gizmos in the picture above. With an impact wrench, the removal of the caps were made easy.

Tony

[fintstone]

My advice is to not even attempt to remove the thermostat from the hard lines. You will likely destroy it or the lines. There is really no reason to ever take the thermostat out (unless you have a leak because someone else already damaged either the thermostat or lines by removing it) because there is no repair that cannot be accomplished with the lines still attached. If your hard lines on the cooler side of the thermostat are gettting very hot as the temp get above 180F or so...it is most likely fine. When the thermostat fails, it is almost always a total failure (not just partially opening). If the line are not getting hot, you can replace those parts for about $60 without ever removing the thermostat. Just remove the large aluminum cap on the side of it as the threads above suggest....and replace the parts from the kit. If you cant get the cap off thet way, drop the entire thermostat and lines down to where you can get to it better. You may have to disconect the lines in the front where you transition fro hard lines to flexible ones. That is usually the eaisest place. If your lines forward of the thermostat are getting hot, the problem is more likely in the sender or gauge...or both.