Large swing in oil pressure- How come?

[Cord]

I too am seeing a low oil pressure when the engine is hot. I'm getting down to 15psi. The pressure drop is steady, but slow. It takes around 45 min to get that low. Cold pressure is OK, around 35psi. Right now I'm using 15w-40 oil and I'm thinking of stepping up to a 20w-50 to see if it doesn't break down from the heat as much.

 

[Cord]

I too am seeing a low oil pressure when the engine is hot. I'm getting down to 15psi. The pressure drop is steady, but slow. It takes around 45 min to get that low. Cold pressure is OK, around 35psi. Right now I'm using 15w-40 oil and I'm thinking of stepping up to a 20w-50 to see if it doesn't break down from the heat as much.

 

[Soundguy]

</font><font color="blue" class="small">( What do you think a minimum safe hot oil pressure would be? 10 PSI at 2,000 RPM would make me nervous.
)</font>

I've heard a rule of thumb of 6psi per thousand.. but that was generic info.

What pressure does the sender open on your unit.. that is the magic number that would make me crack her open.. when it starts letting the oil light come on at idle ( I've seen oil senders that open at 6psi... )

In any case.. having experience with ntique tractors.. status quo is to increase oil viscosity till presure is low on 50w oil.. then rebuild..

Soundguy

 

[Soundguy]

</font><font color="blue" class="small">( What do you think a minimum safe hot oil pressure would be? 10 PSI at 2,000 RPM would make me nervous.
)</font>

I've heard a rule of thumb of 6psi per thousand.. but that was generic info.

What pressure does the sender open on your unit.. that is the magic number that would make me crack her open.. when it starts letting the oil light come on at idle ( I've seen oil senders that open at 6psi... )

In any case.. having experience with ntique tractors.. status quo is to increase oil viscosity till presure is low on 50w oil.. then rebuild..

Soundguy