1985 911 targa oil temperature

[Robert Venning]

Hi, I had the engine in my 911 rebuilt a year ago and the oil temperature never seemed to reach the 90c (second white mark) after that. I never really worried because it was hot where I am and the needle was close enough (and occasionally getting to 90c in traffic or heavy footed driving) but now that the temps have dropped where I live, the needle never goes above the middle between the white marks (sort of its max temp) and it takes an awfully long time to get there. (Image attached)

I am assuming its the engine case thermostat being stuck open but I'd love to get your thoughts on it.

Should I get it fixed asap or is it not a huge deal?
I haven't looked at the thermostat because, as you guys know, it is a major pain to get to.

Also, does my oil pressure seem correct for the temp/revs?, I'm running 10w-40

Thanks in advance.
Rob

[Discseven]

Hi Rob. To check if external thermostat is working... feel the pipes running to front of car. Am not sure what temp external thermo opens at but would think if engine is warm and pipes are not... then in a little while pipes warm up... I'd call that a working external thermo. If pipes warm up along with engine... would call that an open thermo. Oil press looks high for rpm to me. I believe 1 druck per 1k rpm is where it should be but look for confirmation on that.

[Robert Venning]

Thanks Discseven.
The first think I did was tell my mechanic to check the external thermostat. He took it apart, cleaned it and put it back in the car so that should be working fine. I think that this has more to do with the thermostat in the engine which can really only be serviced with the engine out of the car.

Do you think that the temp at which I'm running now can hurt the engine in the long run?

Cheers.
Rob

[rbarton]

I was able to change the engine-mounted thermostat on my '86 without removing the engine. As I recall I pulled the air filter box out and used a cheap flex inspection camera to help 'see'. It wasn't a bad job.

[Robert Venning]

Thanks rbarton.
I was thinking that i might have to take the throttle bodies off but if you were able to i'm sure I can.
Was you're car showing similar symptoms to mine?

[pampadori]

based on the oil pressure in your image and the fact you are using 10w40 are you sure that the motor is fully warmed up?

In the fall and winter here, mine doesn't get much warmer than what you are showing. Everything could be copacetic.

[Robert Venning]

When I took the picture I had been driving for at least 40 minutes (city traffic, stop lights and highway). I am inclined to think that its either a thermostat problem or that the sender isn't reading the correct temp. Down hills, the temp drops substantially and it also does this when getting up beyond 60mph. Even on hot days it wont reach 90c on normal driving.

Maybe the oil pressure sender also needs looking at?

Rob