High tempérenture problem / Overheating problem on 911 T 86 ?

Asked by Dec 07, 2013 at 08:26 AM about the 1986 Porsche 911

Question type: Maintenance & Repair

My 1986 911 Turbo's engine overheating and my engine oil cooler is disconnected. I
wonder if that would be the source of the problem. Also, when the engine runs, the
exhaust is kind of white... Could anyone help me ??

13 Answers


911 has an air cooled engine so there is a additional oil radiator for cooling the engine oil... this must be functioning properly to keep the engine in right temp. if there is some white smoke, the piston rings must be checked, your piston rings are letting some oil in to chamber or your oil is getting over heated and leaking in to combustion chamber but the most important thing to do is to reconnect the oil cooler in its place and using a proper grade oil made for air cooling engine I am using air cooled engine oil made for piston driven air planes

thank's allot, I will do the check up on these thing a give you the result back


Those engines absolutely need the oil cooler(s) to run right. The cooler should never have been disconnected for any reason and then run the engine. Your smoke probably indicates irreversible ring damage, sorry to say. Using aircraft oil on an engine not designed for regular rebuilds is not the way to go. Use the best Porsche recommended oils, they don't contain as much ash, and besides they are designed for automotive use.


The oil in your 911 engine is the "life blood" of your car. This is why Porsche puts 3 gauges in the dash so you can monitor the oil. Oil level, oil temp and oil pressure. The oil level gauge (next to the fuel level in the same gauge circle) works correctly when the engine has reached operating temp. and the car is at idle for about 30 seconds. The oil is even more important for a turbo engine, since the engine runs hard and is under more stress. The oil cooler is connected to a thermostat up inside the left rear fender and circulated into a large reservoir inside the engine compartment. The reservoir is where you check the oil level and add oil. This reservoir contains about 7.5 quarts. If the oil cooler is not connected you are only using about 5 quarts in the engine sump and the car will quickly overheat and possibly cause major engine damage. You should take this fine classic vehicle to an authorized service center immediately before risking any further damage. Get the oil cooler fixed and check compression on all cylinders.


I agree with the above / the oil cooler is absolutely essential to the system for the 911's survival / and use a flatbed hauler (AAA etc) to transport the 911 to the service site.

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Clean oil, good temps. Check your oil temps... Oil should be heated above 212 F to burn off impurities. Never over 250 F. On the occasions it does. It's time of an oil change. Monitoring & managing this will preserve your engine for a long, long time. My air cooled race engine has close to 150 race hours. Full throttle, brake. Full throttle! Brake! Temps and clean oil are so very important.

1 people found this helpful.

Even with the oil cooler functioning properly these engines still overheat sometimes in traffic it's even a good idea if u don't have a fan on your oil cooler to put one on I hope it's not too late for your car


Are you saying the oil cooler is out of the loop? And, oil lines are connected?

I was responding to Raphs question I have an 86 930 that I'm also experiencing overheating I don't now if it's because the cooler lines r pinched by the jacking point or if my car is running lean cuz I have a Mercedes 450 warm up regulator in it wile mine is getting rebuilt by the guys in Texas I believe they r called T auto


Sorry, I was asking Ralph if his Oil cooler is out of the loop completely. That would cause an over heating problem. Bent oil lines don't seam to make a difference. I have had that on my race car for years. Just make sure the are not pinched off. With 60lbs of oil pressure, dented lines don't seam to bother. Always supervise when a tire place puts you on a lift.

Ok that makes sense because my oil cooler is definitely hot and so r the lines coming out of the cooler or I should say the one going in and the return I wonder if it's the wrong warm up regulator then that is making the car run lean


What is a Mercedes warm-up regulator doing in a Porsche air cooled engine.?? Find a Porsche speed shop to fix it right if it's not too late.

Mine is out getting rebuilt so I thought I would put that one in basically to b able to move the car around and I'm sure it's not too late it won't hurt anything the car runs quite well actually but it may be running it a bit lean and hats all I don't think air cooled water cooled has anything to do with warm up regulators

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