Post oil change - High oil pressure

mandm

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Michael
Soooo it’s time for an oil change, an oil change was completed, new oil filter and camguard added. My airplane likes 6 quarts MAXXX (not a cent more) so she got 7 (6+1 for the oil filter) and camguard.

Started her up, did an extended run up, did 3 prop cycles (SHH my mechanic wouldn’t like that), did all my checks, shut down. Went outside and checked the oil levels, the filter, signs for leaks, pulled out my handy flashlight, etc.

NOW the cruddy part, when I was doing the oil change, I have yet to master the skill of removing the old oil filter without making a mess, I have those oil bibs and thought I was doing a good job, only to find a puddle of oil on the floor, basically it’s EVERYWHERE! The oil bib overflowed, failed on my part, that’s ok, I’ll get it right one of these times. Now there is oil everywhere in the cowling, I spent some time cleaning it up best I could but ya know thy fingers cannot fit everywhere.

SO, continuing the story, after the run up, checked for leaks and appeared to be all the oil from before and everything appeared to be ok. Oil levels were fine. Let’s do a test flight, full length runway, short field takeoff, breaks power and go. Everything was working fine then in the climb I noticed that the oil pressure is reading HIGH, like above the max and where it normally goes. Ummmm, I’m thinking what’s going on. Let’s take advantage of the cold weather and gain altitude quickly, all other normal flying checks done with exception I’m keeping in full power and boost pump until I’m a bit more comfortable altitude wise.

Originally requested to fly westbound over the farms for a flight, nice day, why not.

TOWER, request 360s in your airspace. RIGHT 360s approved. Did a couple 360s and oil stabilized, everything looked ok, continued on my journey.

So WHAT happened? Was the engine taking in the new oil and needing time to pump it through? I don’t recall this happening with previous oil changes.

The flight was fine, the oil levels were fine post flight, I took off the cowling back in the hangar, tried to clean up some of the old dirt and oil in there. I’m suspecting maybe an engine screw is weeping some oil (see photo below), and I also think the oil dipstick valve might be weeping some oil at the seal (where it connects at the engine). It’s extremely minimal. It’s been 46-47 hours since my last oil change, and in that time I’ve added 2 quarts of oil, actually I should have only added 1.5 quarts so thy engine is not burning oil. I added 0.5qt extra oil (6.5qt total) on a XC trip and then it (0.5qt) blew out everywhere and made a mess that I’m still cleaning up.


IMG_9521.jpeg
 
What type of oil? What was the outside temperature?
Oil thins with use, so pressure with new oil can be higher, at least initially.
 
IMG_9525.jpeg

This is a photo of my oil pressure but not from the flight. The needle was basically pointing to the number 100. For several minutes. Then went back into the green below the upper red where it normally is. I have noticed oil pressure differences based upon temperatures (for example it will read in the middle green when in Florida).
 
What type of oil? What was the outside temperature?
Oil thins with use, so pressure with new oil can be higher, at least initially.
Phillips xc 20w50
Outside temps today about 5C
 
Interesting. Mine always goes up right after a change and only for a few minutes. But it has never gone red line.
 
I've seen similar behaviors with fresh oil on a cold day in the first couple hours of use.
I'm guessing (experienced A&Ps will most likely chime in) that an oil pump that was adjusted with older/thinner oil on a warm day might be a bit over on a cold day with fresh, thicker oil.
My recollection is that up to 115psi is acceptable for short durations, but I'd have to dig for the documentation to back up my claim.
 
Lyco IO-360-C1C, SAE 50 oil, at 41F? Oh that's normal on the stock gauges before oil gets to operating temp, at least ime. Then again my engine also broke a bunch of bolts inflight, had me PFLing all over kingdom come on a Sunday (instead of "watching" the kid like I told the sleeping frau) and no longer have an airplane....so I wouldn't listen to me either if I were you. :rofl:
 
I've seen similar behaviors with fresh oil on a cold day in the first couple hours of use.
I'm guessing (experienced A&Ps will most likely chime in) that an oil pump that was adjusted with older/thinner oil on a warm day might be a bit over on a cold day with fresh, thicker oil.
My recollection is that up to 115psi is acceptable for short durations, but I'd have to dig for the documentation to back up my claim.
Here's the documentation in question:
Screenshot 2024-03-11 at 9.43.34 AM.png
 
Here's the documentation in question:
View attachment 126561
Interesting because the red line is below 100 if you look at my oil pressure gauge, and maybe I just never paid attention to oil pressure before in the climb phase of flight since I was busy with other tasks. Hmmmmmm
 
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