HELP - oil not going to cooler - C2

[axl911]

The external oil cooler on my C2 doesn't seem to work. My temp guage is close to 250 degrees, but oil doesn't seem to flow to the front oil cooler.

How many thermostats does a 964 have? How can I check its operation?

thanks,
anthony

[Formerly Steve Wilkinson]

I suspect you're not getting any answers because people aren't sure what you're asking. Seems you've already determined that the pipes to the oil cooler are not hot, therefore no flow, and we can assume you've gone one step further and determined whether there's flow to the external thermostat. If there is and it's not getting any farther, there's your problem.

Stephan

[axl911]

I am pretty new to the 911. I am not sure what is the next step to troubleshoot this problem. How do I check the flow to the external thermostat?

I guess there are 2 thermostats?

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anthony

[Formerly Steve Wilkinson]

Well, there's a thermostat in the block that controls flow to an oil cooler on the engine, and a thermostat in the forward part of the right rear wheelwell that controls flow to the cooler at the front of the car. If the big oil lines _to_ the thermostat in the fender are hot but the big oil lines leading forward _from_ that thermostat are not hot, your problem is that the external thermostat is not opening, or, to put it another way, has failed closed.

I don't know whether the internal thermostat is in the loop that leads to the external thermostat, but if not only the lines from the external thermostat but the lines to that thermost are not hot, that means it is in the loop and the problem would be the internal thermostat. Be aware that those lines and hoses to the external thermostat may well be warm simply from heat conducted fromthe engine, but they should be HOT if the oil is actually circulating through them.

Everything is accessible behind the right rear wheel, particularly if you jack that corner of the car up--use a jackstand too--and remove the wheel and tire.

Stephan

[Chuck Moreland]

Hold on - Steve your comments are correct for the pre-964 cars only.

964s have a single, external tstat. It's by the oil tank and controls flow to the front oil cooler.

Sure sounds like it is failed closed.

[Rick Lee]

Your first course of action should be to get the car warmed up and while running, tap on the ext. thermostat with a hammer. Sometimes that will free up the piston, though I'd still plan on replacing it soon. If that doesn't work, some people remove the thermostat and test in in a pot of oil or water on their kitchen stove. I think you can rebuild these thermostats. If that's your problem, I'd get on it. It's a lot cheaper than what running too hot all the time will cost you later.

[banjomike]

I would check that the oil lines are not crushed. The thermostat is also a pressure release valve, and if the lines have been scrunched by a misplaced jack then the thermostat will bypass the cooler to keep oil flowing.

[axl911]

Thanks for the help. Looks like I'll be checking out the oil lines and thermostat this weekend.

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anthony