Oil pressure problem C-85

What about the oil pressure relief valve on the right side of the case? Could be a bad spring, dirt, etc.
Buzz Dolim

Ask your mechanic how many washers under the press. spring, max allowed
is four (AN960) I always start with two, and then go from there. I like 40+
psi COLD. at idle HOT, should not be below 10 psi.(600 rpm). If all that
does not work, check out the vacuum pad. There is an oil hole and oil comes
from the press. side. The gasket might have blown and dumping press oil
into bottom of crankcase. The last item is to remove the Acc. Case and
check out the oil pump area for groves. Hard to see that happen with a
full flow filter, I have seen it happen with the Screen which only keeps nuts
and bolts from going thru the engine!!

My mechanic has checked as much as he can without tearing down the engine. He cut open the oil filter and said there were no metal pieces inside. He checked the pressure relief valve and it was fine. He removed the oil tank to check the pickup tube for leaks and found none. He hooked on his own pressure valve and checked it against the one in the plane. They were identical. He checked the entire engine for leaks and found none. He wants to check the internal oil pump but feels he will have to remove the engine to do so. Has anyone had experience with this? Regards, Larry McCartin N93436

Yes, remove the oils pressure relieve value. It is posable it has a bit of something on it keeping it from seating.
Kevin

You might check for Metal in the oil screen/filter also check the oil pressure
relief valve (Ball) for something in the seat. I have one thing that happened
to me in an 0-200 engine, bad connecting bearing (2)..

In theory, two things are needed to create pressure. A pump that can provide the necessary pressure and volume, and a restriction downstream to maintain the pressure. If there is low pressure, one of those two is compromised. If it isn't the pump, or the gauge, and there are no external oil leaks that would relieve the pressure (that would be pretty obvious), then there has to be an internal failure of either a seal or a bearing. This would be consistent with higher pressure with a cold engine, and as the oil warms up and thins, the pressure drops. This isn't much help, I am afraid, but maybe gives some context.