Running cold - I think

[tgrimmett]

I've had my '84 Carrera for about a year and I am thinking it is running too cold. I don't have one of those numbered oil temp gauges so I can't know for certain, but at best the needle gets about 1/4 way up, barely out of the blue, this is after running for 30-60 minutes on the highway. The engine seems to run fine, though. After reading some other postings, I bought a handheld temp sensor but frankly I'm not sure what to look for and where. The cars up on blocks and wheels off as I am doing the brakes and a number of other random projects. At first I thought that the external thermostat was stuck open and all oil was circulating to the front cooler, keeping it too cool. I only had time to run the engine at idle for about 10 minutes today, but of the four lines attached to the external thermostat, I got a temp of about 170 on the line between the oil tank and the tstat, about 80 on the other line coming from the engine compartment (from the engine I'm not sure), and the two lines that go forward to the cooler were about 120 at the tstat but rapidly cooled to 65 under the car and at the entrance to the cooler. Ambient temp was about 70. So clearly there was no oil being circulated to the cooler.

So any suggestions on where I should point the temp sensor, and at what temp on what line should I look for before I expect the ext tstat to open and start circulating oil to the cooler? I am also wondering if the engine tstat is stuck open.

-Tom

[DRACO A5OG]

That seems quite cool, what grade of oil are you using? Too cold is not good either.

70F Ambient should yield 194-200F after 30 minutes.

TO be certain, you can remove the thermostat in the triangle of death area and do a test in a pot of boiling water to see where it starts to open.

If you do remove it you may want to replace the oring.

[tgrimmett]

Thanks, Draco. I'm not positive on the oil grade - I think 10w-30 or 10w-40. I just changed the oil but the cold running has been an issue for many months. Yesterday I tried running the engine at idle for 30+ minutes and the temp came up to the middle of the gauge and my handheld sensor read about 190-200 degrees on the engine block and oil temp sensor area. I know this is a typical target running temp for other engines - is it a good target for a 911? If so, I know my gauge is OK. And I assume my temp was coming up higher than when I drive because sitting still it didn't have as much cooling affect (I don't have the fan assisted front cooler, just a static cooler). So I think now I need to road test it and see if it is still running cold while underway. Any other suggestions are welcome, and anyone else's experience troubleshooting a cold running engine are welcome too!

[tgrimmett]

Also, I meant to ask what the 'triangle of death area' is? Sounds ominous! I have located the external thermostat easily enough in the right rear wheel well, but is the triangle of death where the engine mounted thermostat is located?