Grant27

I have had this issue slowly persist for some time now, ready to fix it!

Once fully warmed up my '87 924s will show that the oil pressure is fluctuating at idle by quite a bit, going from close to max to almost minimum. I think it has gotten slightly worse over time.

I have also been slowly losing coolant which I am guessing is related to oil pressure issue.

Some generic "ask.com" results said that the bouncing oil pressure has to do with a bad head gasket but didn't explain the reasoning. That idea makes sense to me since a leaky head gasket can sometimes allow the coolant to leak and be burnt up somewhere. I have been regularly checking my oil and making sure it isn't foamy or looking like a "milkshake" and have not seen any irregularities there.



Any help would be greatly appreciated,
Grant

Hollywood D

The bouncing oil pressure gauge could be a bad sending unit or a bad ground.

968 GUY

Could be the oil pressure regulating valve ( OPRV). Does it settle out as you are driving?
Coolant loss could be head gasket, but check the hoses really well. Go to auto parts store and rent a cooling system pressure tester. Check spark plugs for indications of coolant in cylinder.

Grant27

It does settle when I am driving.
I will recheck hoses like you suggested.
How does the cooling system pressure tester work?
What do the spark plugs look like with coolant in cylinder if it is such a small amount of coolant?
Any way to check the sending unit or the bad ground?

Thank you very much for the quick messages for help!

Jamesr6967

If it is a very small loss of coolant, (I have seen this quite often in other vehicles) it could be a small leak at a hose clamp somewhere and gets burnt off by the heat of the engine. Look for colored 'mineral' deposits from the coolant for the source of your leak.