E36 overheating with low oil pressure at idle

[spooling]

e36 m52:

after driving on a hot day i noticed the oil pressure light was on at idle (it would go away when I touch the gas).

Shortly after the engine temp started to rise.

Oil level and coolant level were fine.

Any suggestions where to start?

[propr'one]

check for oil in your coolant, and coolant in your oil.

[noodles101]

just check all ur cooling system.

thermostat , water pump , etc.

[spooling]

would a cooling system issue cause the low oil pressure light to come on?

[sb_600]

could be a failing pump?

[spooling]

i'll try running a pressure test on the cooling system.

[DR.ZED]

The theory would be that the engine oil is getting too hot and thinning out dramatically.

If you have a water to oil, oil cooler then coolant circulates around a heat exchanger to cool the oil. THis means if you are overheating or getting very hot you actually end up heating up the oil instead of cooling it. If you have an air to oil cooler than make sure airflow isn't blocked to that heat exchanger (rad) on the front of the car.

If the oil is a thin viscoscity to begin with then you may just be on the threshold of low oil pressure on a hot day. The "dummy light" probably comes on under 10 psi oil pressure. Now this isn't going to kill the engine, but ofcourse you should now know that your oil is too thin and should go up to a higher second number viscoscity (like a 5w40 or 50).

Small block chevy's rule of thumb used to be 10 psi per 1000 rpm. It was damn scary seeing my LT1 in my Camaro sitting near the redline of oil pressure on a hot day, but it was okay.

[spooling]

Thanks Zed, I'll take a look when we have a nice day.

[dil]

had this problem in my e36 only way i got it fixed and gone for good was headgasket but that may not be your problem

[spooling]

I'm hoping its the cooling system. I was running 5-30 on a hot day. My car runs hot already since its boosted. There is no oil in coolant or coolant in oil and zero smoke from the car. It still runs great just hot.

I'll be checking this week when I get a chance.

Will update when issue is found.

[naui16865]

What's the mileage on the car and is the cooling system orig?

I've had creeping engine temp probs in hot weather due to a siezed aux fan (98 M3). It's easy to check and an easy fix if found to be failed.

I've also had unexplained low oil pressure warning in hot weather at idle (same 98 M3 at about 240k Km). Changed oil pressure sensor to correct. Again, low cost, simple repair if found faulty.

The combination of a weak sensor and creeping engine temp will give low pressure warning. Recommend you confirm cooling system operation and correct sensor-operation before leaping to more complicated (expensive) fault-condition explanations.

[spooling]

Thanks everyone for all the responses.

I found the issue, my engine fan was on the way out. I will be replacing with an electric fan and the corresponding cooling upgrades (maybe even an oil cooler for my turbo ).

[BmW1819]

what about the oil pressure??? cause the engine temp was to high ??

[spooling]

yea exactly. The engine heat was thinning the oil. Not to mention it was an extremely hot day and I was downtown.

[BmW1819]

yea it all makes sense what oil are u using??