High Oil Temp
06-17-2003, 07:02 PM
#1
Racer
Thread Starter
High Oil Temp
My close friend's 88 Carrera oil temp is just above the 10:00 mark on the gauge, driving at modest speeds (30-40) with outside temp around 75 degrees. The oil lines to/from the front oil cooler are hot but the front oil cooler's fan isn't running. Can anyone tell me how to jump the fan to make it run? Not sure if it's the fan's thermostat or the fan itself that's the problem.
Actually I'm surprised the oil temp is this high even without the fan running, given the modest engine load and cool ambient temp. Any ideas? Thanks
Actually I'm surprised the oil temp is this high even without the fan running, given the modest engine load and cool ambient temp. Any ideas? Thanks
06-18-2003, 07:17 PM
#2
Rennlist Member
It sounds like maybe more than the fan. I have an 86 that is the same system sans the fan. I am concerned with temps occaisionally approaching the 10 o'clock line (250 degrees) while in heavy traffic, going upo hill, A/C blowing and 105+ degrees outside. So, at 75 deg without the fan working, I'd suspect there is somethind else amiss. Maybe mashed lines, bad thermo, temp sensor, etc. I'd be concerned if the gauge [if properly functioning] exceeds 9 o'clock.
todd
86 cpe
todd
86 cpe
06-18-2003, 10:25 PM
#3
RL Technical Advisor
Dick,...Todd:
First,.....I'll tell you that 250 degree oil temps are too darned hot for any kind of engine life and will truly shorten the durability of valve guides and the seals/gaskets in the engine. IMHO, this calls for some kind of resolution. At 75 deg F in normal street use, you should not see oil temps that high, unless there is some kind of problem.
Oil cooler fans are really intended for idling in traffic and where there is little natural airflow though the cooler. Once you are moving above 40 MPH, the fan is of little or no value in cooling the oil.
Given the size of the factory Carrera cooler and its limited airflow from the front of the car, the conditions you mentioned above will result in oil temperatures that will compromise the longevity of the engine. Frankly, its not quite large enough for situations like these.
All that said, I'd make sure that everything is on good shape and operating properly before spening any $$$ for an upgrade. These cars have two oil thermostats that do give some trouble over time; one is mounted at the top of the engine above the bellhousing and the other one is in the right rear fenderwell just ahead of the tire. If one or both fails to open all the way or gets sluggish, you can see excessive oil temperatures rather easily. Other things are making sure that the oil lines running under the right side have not been accidently flattened by an errant floor jack or garage lift.
For Todd: Given the summer AZ weather, you might need to investigate adding a second oil cooler, if you expect that engine to last as long as its capable of.
First,.....I'll tell you that 250 degree oil temps are too darned hot for any kind of engine life and will truly shorten the durability of valve guides and the seals/gaskets in the engine. IMHO, this calls for some kind of resolution. At 75 deg F in normal street use, you should not see oil temps that high, unless there is some kind of problem.
Oil cooler fans are really intended for idling in traffic and where there is little natural airflow though the cooler. Once you are moving above 40 MPH, the fan is of little or no value in cooling the oil.
Given the size of the factory Carrera cooler and its limited airflow from the front of the car, the conditions you mentioned above will result in oil temperatures that will compromise the longevity of the engine. Frankly, its not quite large enough for situations like these.
All that said, I'd make sure that everything is on good shape and operating properly before spening any $$$ for an upgrade. These cars have two oil thermostats that do give some trouble over time; one is mounted at the top of the engine above the bellhousing and the other one is in the right rear fenderwell just ahead of the tire. If one or both fails to open all the way or gets sluggish, you can see excessive oil temperatures rather easily. Other things are making sure that the oil lines running under the right side have not been accidently flattened by an errant floor jack or garage lift.
For Todd: Given the summer AZ weather, you might need to investigate adding a second oil cooler, if you expect that engine to last as long as its capable of.