High RPM engine overheating

OSC911 · 12-25-2003, 12:28 AM

A failly long description but bear with me here:

I have a concern that arose the other day with my '79 ROW SC that I hope someone out there can shed some light on. I was taking a fairly aggressive drive up a mountain range about 30 min from my house using 2nd and 3rd gear when I noticed the oil temp was high at about 3/4 - 7/8 which it has never been. I was working it fairly hard using the higher end of the rev range. The ambient temperature over here on that day was 35C/approx. 95F as it is in the middle of summer.

Soon after this it seemed to loose power quite badly and at this stage I headed home and nursed it all the way. As the temp. came down to the normal position on the gauge the power came back to normal.

I searched througe my Exellence mags. and found a tech. article which suggests it could be a early SC oil pick up screen prob. that allows not enough oit to return to the oil tank and thus filling the crankcase with oil. I only have a loop type cooler if that helps also.

Any ideas and suggestions would be a great help.

Todd

911 SC
Toyota Landcruiser
Toyota Hilux

RoninLB · 12-25-2003, 02:27 AM

I remember when I had only a loop for a cooler that it would start to have elevated oil temps at 3.5k+ rpm in desert heat on a flat road. I never allowed it to get past mid way on the gauge. A cooler installed in place of the loop cooled the oil temps down big time. I also assume the loop is getting oil thru the thermostat. An SC has more hp than a 2.7 so it needs more cooling to begin with.
Get a new fender oil cooler at least.

Larry Harris · 12-25-2003, 05:29 AM

Check your oil thermostat to make sure it is opening fully. Had a similar problem with a euro 2.7 and a new thermostat solved the heat problem immediately.

Merry Christmas

earossi · 12-25-2003, 05:45 AM

Though a fender mounted oil cooler would be a nice upgrade, I don't necessarilly subscribe to it at this point. The basic issue is that you car was working okay...........and then something changed that caused it to overheat. If the issue was the oil screen, you would have had the problem long ago. And, if the problem was an insufficient oil cooler...........again, you would have noticed the problem long ago.

As the previous poster suggested, look for something that has moving parts that has failed. The first and most obvious item to focus on is the thrermostat. If the stat is frozen closed, you will not have the advantage of the oil cooler whether it be the trombone type or the newer radiator type.

If you elect to replace the thermostat, I would advise you to break down and spend the $50 for the set of Porsche oil line wrenches. They are crude and not pretty to look at, but they will make breaking all the large oil line fitting loose a breeze.

As an afterthought, you may want to determine if your trombone oil cooler is hot to the touch. If it is not hot, then you know that the thermostat has failed closed. If it is warm, you may still have a bad thermostat that is failed partially open. But, if you are seeing oil temps above 300 degrees, the cooler should be too hot to touch!!

Let us know what you find out.

OSC911 · 12-25-2003, 10:19 PM

Thanks for the reply. I have already started to remove oil thermostats for testing and or replacement. I will also start saving for a radiator style cooler which is certainlt needed in the temps we se over here.

I have also drained the oil and removed the scavanger pump oil pick up screen and it is the type that Bruce Anderson describes as being a problem. Aparently it should have been replaced under warranty on a recall program in late '79 with a venturi style. I will order one of these when the dealer opens after the holidays.

Once again thanks

Todd

konish · 12-25-2003, 10:30 PM

Mate,
Check this out....seems like another Pelican ahd the same prob and really benefited from the new type of sump screen. I'd give that a shot first, then add the big $$$ cooler if it doesn't pan out...

R/
Dustin

Source for SC oil sump screen update?