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Intermittent High Oil Pressure

Flying8

Active Member
SO on my O-320-B2C I am experiencing intermittently high oil pressure over 90 PSI. Normally on takeoff roll where I end up aborting... Pull off the runway and kill the engine by pulling the mixture. Start back up and all is normal, like I freed something or unstuck something within the system.

Pulled out trusty Lycoming troubleshooting procedures and I inspected the oil pressure relief valve. All seems normal. Ran copper wire down the return tube to sump and didn't find blockage. First oil sample since owning the plane didn't have any red flags for a 2500 SMOH engine. All other signs lead to a healthy engine, compression, very low oil consumption etc.. Yes it is a high time engine but the airplane has been used very frequently.

I have a GRT Sport EX for the EFIS/engine monitor. My next move would be to find a mechanical gauge to temp install to see if it is a faulty reading.

Any tips?
 
2nd gauge is a good idea. Do you upload data to Savvyaviation.com? If so, you might see something in the oil pressure over time that might tell you if it's real or an indication problem.
 
I have not. I will need to read the manual to figure out how to download it. Should be simple enough. I would imagine if I spun a bearing, simply shutting down the engine would not "reset" the problem as it has several times now.
 
How high over 90 psi? What is your oil temperature when it goes over 90?
What oil are you running? What is the OAT when this happens?

I occasionally got oil pressure up to 90 - 91 psi on take off momentarily during the first flight of the day when running W100. Oil temp was always 100 degrees or better.

As suggested I would confirm the pressure with a 2nd gauge. If correct and if your oil pressure is only marginally over 90 psi I would go with it and see how long it lasts.
 
Temperature has no effect. It has been on first start of the day, as well as after flying it for 30 minutes. It has happened in OAT of over 100 degrees as well as 65 degrees OAT. W100Plus. The last flight this happened I got airborne and it stayed well over 90 and I had to basically limp the airplane back to the field by pulling the power almost to idle and it was still up at 88/89 PSI.

Again it doesn't happen every flight.
 
I would put the blame on the sender. Had a similar occurrence. A “fix” that GRT says to try is to whack the sender. Did that, and sure enough, was ok….for awhile. Have since replaced the sender.
 
Ok now reading more about it, the sender seems like a good starting point. Appreciate the help!
 
Just closing this squawk. It was a VDO Sender. Replaced with unit from Spruce. Works great. No more fluctuations. Thanks for assistance!
 
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