After our last annual the left engine on our PA30 Turbo indicates high oil pressure during run up and at takeoff power; almost to redline but not quite. During start and taxi it is normal.
After a short period of time, about the time you would take to exit the airport traffic pattern it returns to the center of the green marking and remains there for the remainder of the flight. Oil temps and all other indications are normal.

Prior to annual it was always right in the middle of the "green arc."
During annual, we replaced both oil coolers with new units due to cracks and of course a new oil filters were placed on the plane.
Other than that, nothing really changed... any ideas what may be causing this issue?

Chris,

What does the mechanic that did the annual have to say?

Any chance the type of oil was changed also?

When I ran Exxon 20W50 the twin had higher oil pressures. I changed back to aeroshell 15W50 and they went back to normal. I will say, the oil pressures run higher at take-off but hadn't watched during run-up - will do that today.

Hi Pat,

Our Mechaninc is at a bit of a loss.
We cleaned the Oil Pressure regulator but that did not help.
The oil was changed, but we continue to use 15w50 so no change there.
The right engine is indicating as it had prior to any of this... it is just happening on the left and it is significantly different from the right.
I am wondering if the issue could be the new Oil Cooler (both were replaced,) perhaps it is causing the problem??
chris

I've had oil coolers flushed/overhauled and they didn't get all the crud out causing high oil temp but it could cause high oil pressure. Compare you left/right oil temp when one side has the high oil pressure. Some of the stuff could make it's way to the oil pressure relief valve and keep it closed or screw up the veernatherm in the cooler. bernie

Chris,

Hard to say. Wish you had a JPI engine monitor to help - in the computer world when something didn't work, it was procedure to look at whatever was last changed so I think your thought on looking at the oil cooler is a good one.

One the other hand, things do break and the cluster gauges do get old.

If it were me, I'd look closely at the oil cooler. Was it new? Is there a warranty? There is also possible contamination during remove and install or just residual crud somewhere in the system.

Hope to hear what solves the problem so we can all learn.

Thank you, Pat.

I am highly suspicious of the oil cooler and the change out process, as both you and Bernie have stated.
It is a brand new unit, cost between overhaul and new is very close so I opted for new.
I will certainly let everyone know what we find, for future reference, if we ever solve this.

Best,
Chris

Chris,

Were any new hoses made for the new oil coolers? If so and the proper mandrel was not used to insert the fitting into the hose, it is possible to peel up a flap of rubber from the inside of the hose and this can create a flapper that will restrict the oil flow. As the oil warms, it will get thinner and pass through the restriction with lower pressure.

Wayne Haristy
N7877P
4R7

Wayne,
I am not sure if new hoses were made or not.
I will ask and let you know.

This could be the clue we are looking for because as the oil heats, it is no longer an issue.
It took me a while to notice this problem after annual because each flight after the annual included a trip to the self serve pumps. Then a restart and another taxi prior to run-up or takeoff resulting in pretty warm oil.
It was not until I was at an airport away from home where I made a cold start - taxi out - run up and departure... then I saw the problem. You may be on something here.

Thank you for you input.
I will report back.

Chris

Just a quick update.

We changed the left oil filter.
No changes to oil pressure issue, left was still higher than the right.
We then swapped the new oil coolers to see if the problem would follow the oil cooler.
No luck.
The oil pressure is slightly lower than before on the left engine, but still higher than the right.
It is not in the red but certainly in the high part of the yellow arc.
Oil temp on the left engine does warm faster than the right, but once stabilized they match up, just as the pressures do, for the remainder of the flight and post flight.

chris

A wise man once told me that every engine is a unique science experiment. Fly on! I don't see any of this as a problem.
-Zach