I have a 1973 911 with the 2.4L MFI motor. My question concerns whats considered normal oil temp operating range and whats considered high. The other day, after driving my car about 45 or so miles, I noticed that the temp gage was above 210. I wouls estimate about 220 to 230 degrees. Outside temps were in the upper 60's to low 70's. Is this normal or should I be looking for a problem somewhere?
Thanks,
Scott Harris
1973 911T Targa

 

911 engine operating oil temperature should be around 200 deg. F.

The proper operating range is 180 deg. F to 220 deg F.

 

Okay, on Sunday I took the car for a nice 180 mile ride through some twisty roads in Kentucky. My oil temp gage was hovering around 250 degrees. The Temp would drop to the 200-240 range when the RPMs dropped below 3000. I checked my oil level and it was perfect. My engine is a 2.4L MFI rebuilt about 1500 miles ago, stock. I am worried about these high temps. Also, the oil level gage was almost pegged at the upper end of the scale when the hgh temps were happening. Do I need a new oil cooler? Do I need an external oil cooler? Am I over reacting?
Scott Harris
1973 911T Targa 2.4L MFI

 

Hi Scott:

Assuming for the moment that your gauge and sender are accurate, IMHO your oil temps are too high for a 2.4 T motor. Here are some things that you should check quite thoroughly as soon as you can that can generate overly hot oil temps:

1) Ignition timing

2) Engine oil thermostat

3) Oil level too high. Ignore the gauge; always check the oil by the dipstick

4) Vacuum leaks

5) Obstructed muffler (rare, but this does happen)

6) Old leaky spark plug connector sealing boots

7) Dare I mention it?,.........something obstructing the cooling air from the engine mounted oil cooler. You'd need to remove the cooling fan assembly to take a peek.

After confirming all this, I'd have your shop do a compression & leakdown test. These small low compression engines do not run hot and if everything above is OK, this needs some serious and immediate followup.

I've never needed to install front coolers on these cars unless they were air-conditioned or operated in really hot weather; 90+deg and 90%.

 

Steve,
Does the engine oil thermostat operate like a thermostat in a water cooled engine? If it does, then it could be sticking and not allowing full oil flow? Where on the engine is it? Is it on the top back behinf the MFI pump?

Thanks,
Scott Harris
1973 911T Targa 2.4L MFI

 

Hi Scott:

Yessir. This device starts to open around 180 deg F and they can go bad by not opening all the way. These can removed and tested in boiling water with an accurate thermometer.

It is located on top of the motor very close to the front (flywheel) end and easily visible with the aircleaner removed. Its slightly offset on the right side of center, close to the breather hose.........

Its silver in color and held in place by 2 small bolts.

 

Steve,
I found it. Seems easy to remove. Next question is.... Where can I get a replacement? And, is there a lower opening temp available?

Thanks,
Scott Harris
1973 911T Targa 2.4L MFI

 

Hi Scott:

The only one is the Factory one and frankly, its damned good.

Like anything mechanical, these can go bad after some time.

 

I have a question- what weight oil are you using? I have always used 20W-50- I do most of my driving in the summer, and have had a '78, then '87, and now '93 911. I don't know if the recommended oil is the same for a '73, but being as these motors are oil/air cooled, I would try some heavier oil for non-winter driving.

Andrew

 

I run only 20W-50. I use Castrol GTX non-synthetic. I change the oil every spring, and I generally don't drive the car in the winter. My oil level is right in the middle range on the dipstick. I am trying to find a oil thermostat, but no one seems to sell them.
Steve, do you guys at Rennsport Systems sell these oil thermostats? If you do give me a price. Also what about these in line coolers I see that fit inbetween the oil tank and the cooler? Worth the $250 asking price?
Thanks,
Scott Harris
1973 911T Targa 2.4L MFI

 

Scott,

My 2.4L engine was getting quite warm last year during AutoX. During normal driving (highway, city stop n go) it rarely touched the 210 mark.

A few weeks ago, I took the fan and alternator off and discovered that the cooling fins were covered in muck. I cleaned them with Engine cleaner and, hopefully, this solves my problem.

I am certain the Porsche Dealer or the major parts houses (Paragon, Pelican) have the part. If it is not in the on-line catalog, call the 800 number and ask.

I am sketical of the compact cooler you are refering to but, hey, it can't hurt.

 

Scott,

I have a carbed 2.4S. I drove it an hour this afternoon when it was about 80. I don't have a front oil cooler and my temperature slightly broke 210 after cruising over 80 mph for an extended period.

Check whether the thermostat is working properly before buying a new one.

 

The problem is that I can't seem to find anyone selling the engine oil thermostat. I really need a price. Any help with pricing? I realize that if I contact a dealer that it will probably cost 600 or 800 dollars. Everything seems to at the dealers. I have tried Pelican and they never return my calls. I am trying to find best pricing for this part.

Scott Harris
1973 9111T Targa 2.4L MFI

 

Scott,

Have you TESTED your current thermostat yet? Replacing it might not even solve your problem. Was your engine running hot before the rebuild, since the rebuild or just recently?

The part you are looking for is 93010776500. Stoddard sells it for $167.45, but their site says "Call for availability".

Once again, I would check other possible causes before changing out the thermostat.

 

Hang in there,Scott. You'll get it figured out.

85' Carrera Coupe 3.2