I searched the forums, but didn't really find a definite answer. I have an 06 Evo IX, and today the oil temperature shot way up. I have defi gauges and it shot up to 150C (over 300 degrees F). I felt the oil cooler and it was not hot at all. I am thinking that the oil cooler thermostat went bad. I was looking in the service manual and I couldn't find the location of this thermostat, or if it even exists. The oil was at the proper level and the engine temperature was normal. Any ideas or questions?

 

Also the oil pressure is normal, so it isn't a pump issue.

 

Very odd! I know allot of people that dont even run the oil cooler anymore with no problems at all. What were you doing when this happened? Racing? What type of Racing?

Chris

 

normal driving, even drove without hitting boost to see if that was the problem, but it just kept shooting up after i let it cool. I also thought it may be a bad temp sensor, but the valve cover and oil line to the turbo was scalding hot, so I trust the gauges.

 

I remember the first time I installed my downpipe I had a huge exhaust leak. After the install the first time, my oil temps were a lot higher because of the exhaust gasses hitting the oil pan. I fixed the leak and then temps went back to normal. Could it be possible you have a big leak there?

 

You sure you install the oil temp sensor to the right location? pic?? I have Swoosh oil temp gauge and it's been around 180 to 190 highway driving for 2 hours or so at ave 80 mph.

 

Oil Temp was fine up until I put in a new clutch last week. I had to remove the downpipe, so maybe there is an exhaust leak there, I'll check that out. Thanks!

 

how long does it take for oil to cool down? The car has been sitting for 7 hours and it is fairly cool out (less than 50 degrees F). I just turned on the ignition key and the oil temp gauge is reading 90 degrees C (194F). I would think that it would have cooled down a lot more than this, so I am thinking the sensor took a dump. I know oil stays warm for a long time, but it can't be that hot for 7 hours. Any ideas?

 

ok, I think i may have figured out the problem. I checked the engine with a thermal imaging camera with temperature readout. The valve covers were a steady 133F and to my surprise, the defi gauge was reading 133C. I think somehow the control unit converted the gauge to F instead of C. The oil cooler was working and was reading about 130F (was sitting at idle for a while). So it seems everything is in working order. Is there any way to convert the defi control unit to degrees C? or is my probe to blame? Any help would be appreciated

 

if the gauge "somehow" converted to read F instead of C 300 degrees F is still to hot. i would check to make sure that the gauge is properly grounded and there isnt any insulation rubbed off of the wiring and causing the gauge to ground.

 

It was reading 150C, which I converted to degrees F. If the gauges did switch, it was only 150F. I checked the wires and nothing was out of sorts. Troubling indeed.

 

How old is the gauge/sensor?
Are you using the sensor the gauge came with?