911 running to cool?

[911Jarle]

Hello guys!

Been reading a bit on oil temperatures, and that leads to believe that my car might be running a bit to cool...

After 5-10 minutes with slow warm up driving, my car gets to around 120. After 15 minutes of driving it is in the 140-150 range. In slow traffic I rarely see more than 160, highest I've seen is 180 after an hour in stop and go.

My car has been run in California, so perhaps the thermostat is a bit to willing for the Norwegian climate? It is a 1979 3.0 With oil cooler..

What do you think guys?

Thanks!

Cheers, Jarle

[E Sully]

What is the outside temperature when you are driving? After 15 minutes of driving and the temperature is 140-150, check to see if the two oil lines to the front cooler are hot. If the cooler and the lines are heating up, the thermostat may be stuck open. Oil should not be going to the front cooler at those temps.

[dshepp806]

Possible thermostat issue?

As noted , all relevant to outside temps.......(real world).

Best,

Doyle

[Tyson Schmidt]

Either you have a mismatched sender and gauge, or you have a malfunctioning or non-existing thermostat for the auxiliary oil cooler.

[T77911S]

911 running too cool. huh, i had to check this on e out. who would have ever thought.

[911Jarle]

Originally Posted by E Sully

What is the outside temperature when you are driving? After 15 minutes of driving and the temperature is 140-150, check to see if the two oil lines to the front cooler are hot. If the cooler and the lines are heating up, the thermostat may be stuck open. Oil should not be going to the front cooler at those temps.

I'd say around 20-25C. And yes, the pipes going forwards are hot, meaning oil is definately going there.. Where is the thermostat located?

Thanks!

Cheers, Jarle

[911Jarle]

Originally Posted by Tyson Schmidt

Either you have a mismatched sender and gauge, or you have a malfunctioning or non-existing thermostat for the auxiliary oil cooler.

I know there has been a much bigger engine in the car earlier. I am thinking the thermostat is matched vs a bigger engine and warmer climate.. I need to check for that Thermostat.

Thanks!

Cheers, Jarle

[911Jarle]

Originally Posted by T77911S

911 running too cool. huh, i had to check this on e out. who would have ever thought.

Weird one I know

Cheers, Jarle

[Dr J]

There is another possibility. My car was running hot and apparently the thermostat to the oil front cooler can have the thing that activates it removed. The result is that you essentially have an open thermostat and oil flows to the front oil cooler as soon as the engine is started.

I once took mine to the mechanic because I thought the thermostat opened too late and apparently they removed the plug inside the thermostat. The result was that after driving in Miami (80-90F) for over half an hour, it still wouldnt reach 180F which is about ideal. I took it back, they replaced the innards of the thermostat and once again, it allowed the vehicle to warm up normally.

Check if you can feel oil pumping or a slight temperature change in the oil lines to the front cooler after you start it up cold.

[911Jarle]

Originally Posted by Dr J

There is another possibility. My car was running hot and apparently the thermostat to the oil front cooler can have the thing that activates it removed. The result is that you essentially have an open thermostat and oil flows to the front oil cooler as soon as the engine is started.

I once took mine to the mechanic because I thought the thermostat opened too late and apparently they removed the plug inside the thermostat. The result was that after driving in Miami (80-90F) for over half an hour, it still wouldnt reach 180F which is about ideal. I took it back, they replaced the innards of the thermostat and once again, it allowed the vehicle to warm up normally.

Check if you can feel oil pumping or a slight temperature change in the oil lines to the front cooler after you start it up cold.

I had quite a bit of heat in the front lines when the engine was at 140. So it's definately pumping oil to early or all the time. Where is the thermostat located, do you know?

Thanks!

Cheers, Jarle

[E Sully]

The thermostat is located just in front of the right rear tire.

[tcar]

Originally Posted by 911Jarle

I had quite a bit of heat in the front lines when the engine was at 140. So it's definately pumping oil to early or all the time. Where is the thermostat located, do you know?

Thanks!

Cheers, Jarle

In the front of the RR tire in the wheel well.

It shouldn't open until it reaches 180 F. roughly, I believe. So the oil should stay at 180 at a minimum.

[911Jarle]

Originally Posted by tcar

In the front of the RR tire in the wheel well.

It shouldn't open until it reaches 180 F. roughly, I believe. So the oil should stay at 180 at a minimum.

I've done a bit more testing.

I don't think the thermostat is missing or stuck open. But I don't think it is an original SC thermostat either. To me it seems the thermostat is working, but is opening much to early. My guess is around 140..

I guess I can change the internals somehow?
Which part am I looking for?
Porsche 911 & Carrera Oil Circulation - Page 3

Thanks!

Cheers, Jarle

[E Sully]

Can you post a picture so we can see if your thermostat is original. Any numbers on it?

[911Jarle]

Originally Posted by E Sully

Can you post a picture so we can see if your thermostat is original. Any numbers on it?

There is a lid in front of it, when the rain clears up I'll go out and take a picture of it..

Thanks!

Cheers, Jarle

[newms]

I don't believe the thermostat would make any difference. After 15-20 minutes of driving everything should be warmed up no matter what cooler/thermostat you have. No 911 engine will run at 160 degrees. Your problem is most likely a bad or incorrect guage/sender. Do you have a numeric oil temp guage?

[d.a.autry]

Originally Posted by newms

Your problem is most likely a bad or incorrect guage/sender. Do you have a numeric oil temp guage?

I just posted on this subject in a different thread. Do a mechanical check of temperature. There are some threads on 'calibrating' the sender. Essentially you remove the sender, Jumper from the terminal of the sender to the harness connector, jumper from sender housing to a chassis ground, emerse the probe in a small metal cup filled with oil, then heat it. You'll need a suitable thermometer that goes up to around 150C. By comparing the known good temp reading of the thermometer to what you see on the gauge you can at least then see if there is any descrepancies

ANYway, whether you choose to go through that or not, double check the sender. I think that many senders that should be 150C max have been replaced with a 200C max sender thereby give false readings on the low side. You'll have to identify your gauge though and ensure exactly what sender it needs.

[911Jarle]

Originally Posted by Tyson Schmidt

Either you have a mismatched sender and gauge, or you have a malfunctioning or non-existing thermostat for the auxiliary oil cooler.

After I posted here, I bought a infrared temp measurent tool.
It shows around 70-75C on the outside of the oil cooler pipe by the front wheel.
It also measures about 75C on the outside of the oil reservoir.
The gauge still shows about 140 F, which leads me to belive the sender and gauge is missmatched.

70-75C on the outside must mean 5C to 10C higher on the inside, meaning that my thermostat is probably working OK. The oil will probably cool a bit along that long pipe, so it is likely the oil is more than 10C hotter than what can be measured on the outside.

Any comments anyone?

Cheers, Jarle

[fintstone]

Either your gauge is bad, your sender is bad....or the two are mismatched.