Oil pressure and temp

[NRW-Aviator]

Glen, Iḿ using Shell W80+ . Now Iḿ using the bypass device. There was no change in elevation. My airflield has 120' MSL and crusiing altitude is around 3000. The outside temp is a little higher, but not that much (30°C)
I tried to adjust the pressure with a new ball and new spring. So now the pressure at take off is at 90PSI ( light in the yellow), at cruise at 2400 (leaned) it dropps to the middle of the green arc. After a while (maybe 1h) with no changes it dropps to th lower end of the green arc and is pulsing.

I asked a Lycoming guy and his worst thought was a worn oil pump.
https://share.icloud.com/photos/0qGd...QuQ1yg_JTk26bA

[Steve Pierce]

Sodid this start all of a sudden? At those outside air temperatures I would run W100 oil. I take it you do not have an adjustable oil pressure relief valve so you would need to shim the spring with AN960-10 washers. Curious if any work was done and the history of the engine. If you have a new style oil pressure seat and an old style oil pressre relief valve cap you will have low oil pressure and fluctuation.

[NRW-Aviator]

Steve, last march I noticed this low oil pressure the first time. And now I've an eye on it every time. These high temperature are only a few days/weeks. Normaly we have 15 to 22 degree in summer.

I have the old style pressure relief with the spring, washer and the old style cap. With the new ball and new spring I adjusted the oil pressure at TO at 90 PSI. That is the beginning of the yellow arc. After reducing the throttle the oil pressure drops to 75 PSI and stays there stable. In my opinion that is a good adjustment. Oil Temperatur is at 180/190.

[Pacerfgoe]

Since there was a noticeable change (last March) without any input from you, have you tried a separate gauge to confirm that the pressure readings are correct?

My plane runs all day long at 210 in the summer, and about 170-180 in the winter with most of it blocked. I wouldn't worry at all about 200 degrees, that's a good temp.....230 -240 is hot, when it gets to 250 or above, that is the temperature where thermal breakdown starts occurring.

Confirm your pressures....

[Steve Pierce]

Steve, last march I noticed this low oil pressure the first time. And now I've an eye on it every time. These high temperature are only a few days/weeks. Normaly we have 15 to 22 degree in summer.

I have the old style pressure relief with the spring, washer and the old style cap. With the new ball and new spring I adjusted the oil pressure at TO at 90 PSI. That is the beginning of the yellow arc. After reducing the throttle the oil pressure drops to 75 PSI and stays there stable. In my opinion that is a good adjustment. Oil Temperatur is at 180/190.

Sounds like you got it fixed.

[NRW-Aviator]

That was my wish, but.... the oil pressure drops again in the yellow arc. Next step is to check the oil pump.

[Steve Pierce]

Anything in the pressure screen, what about the suction screen?

[NRW-Aviator]

The pressure screen is ok. Only some of these black dots, like sand. But the suction screen, to tell the truth, it was never checked ��

[NRW-Aviator]

Today I checked the oil pump. What do you think? It doesn’t look so bad.


IMG_8681.JPGIMG_8683.JPG

[Pacerfgoe]

Doesn't look too bad to me....just looks used.you might try measuring the thickness of the gears, and then the depth of the pump case to get an idea of the clearance. Also use a feeler gauge the see what the clearance is between the gear tip and the pump case.
Once you have this info you should be able to consult the overhaul manual for where your at wear wise.