Oil pressure

[Phantom17]

What is an ideal oil pressure at idle and at wot? <br />My gauge is jumpy and reads between 20-40 (inline 4).

 

[RubberFrog]

Re: Oil pressure

I asked a similar question a while back. My 3.0 sits bewtween about 30 and 40 at idle. I was told that's ok. By one person.

 

[marinemech1]

Re: Oil pressure

if you want to connect a mechanical gauge into the engine.<br />20 psi is ok

 

[marinemech1]

Re: Oil pressure

i heard from omc service that minimum oil pressure of gm engines is 8 psi at idle<br />i like to see more 20+

 

[Phantom17]

Re: Oil pressure

You should see this thing bounce. It's probably normal for a 1981 gauge, but it makes me a bit nervous......

 

[Phantom17]

Re: Oil pressure

only 20 eh? I would have expected that 40-60 was more normal. Thanks.

 

[Don S]

Re: Oil pressure

Put a mechanical gauge on it to test for actual oil pressure. You probably have a gauge or sender problem, even a loose or corroded connection. But if the pressure is acutally ok and verified with the mechanical gauge, then just find and fix the problem.

 

[Silvertip]

Re: Oil pressure

As a rule of thumb for GM engines, oil pressure should be roughly 10 PSI/1000 RPM. Generally it will be between 25 and about 40 at idle (engine warm). Hot oil after a long WOT run may result in readings in the 10# range at idle but that's perfectly acceptable. Another rule of thumb is as long as you have "some" oil pressure at idle and normal pressure at cruise, you are still ok. I've seen engines run a good long time with very low idle oil pressure. It's a sign however, that the bottom end of the engine is getting a little used.

 

[trog100]

Re: Oil pressure

true engine oil pressure varies massively between hot and cold oil.. there is pressure relief valve built in to stop too much oil pressure building up with cold oil.. without it the pressure at higher revs would be so great it could shear oil pump drives and blow seals.. <br /><br />its pressure when hot that should be taken notice of.. 8/10 at idle would be okay and 40 at higher revs would also be okay..<br /><br />my electric gauge flicks about between 20 and 40 hot or cold and is quite clearly useless at telling me my real oil pressure.. still at least i know i have some oil pressure which is all that matters really.. cos short of a complete rebuild there aint much u can do about it..<br /><br />there aint no ideal oil pressure.. just as long as there is a plentyfull supply going around..<br /><br />tight new bearings might produce a higher pressure but they also reduce the oil flow.. flow is probably more important than pressure.. oil flow keeps the cranshaft bearings cool.. if they get too hot they fail dramatically..<br /><br />when u fire an engine up.. just make sure there is some oil pressure.. dont overly worry about what it is.. and its pressure when hot that matters.. even a worn out engine with loose bearing clearances will produce plenty when cold..<br /><br />trog100