Oil pressure

[magnesium]

I have a 350, 1976... When cold, oil pressure is at 40, When hot, oil pressure at idle speed is about 20... hot, cruising speeed about 30... is this normal? or too low???

 

[vetteboy86]

compared to my 86 it is low, however that could be possible. I am sure someone else here has the same year that can clear things up.

craig

 

[magnesium]

it starts to worry me... what can be faulty???

 

[Tom73]

I have a 350, 1976... When cold, oil pressure is at 40, When hot, oil pressure at idle speed is about 20... hot, cruising speeed about 30... is this normal? or too low???

The standard for 73, and I assume that the 76 would be close to the same, was 40psi at 2000 rpm.

tom...

 

[magnesium]

Thanks guys...

Is a faulty sensor can be the cause? what else can trigger this problem?

 

[Tom73]

Could be a sender, or could be because of worn bearings I would double check it with a mech pressure guage to confirm the numbers.

tom...

 

[TheRedVikingSE]

are you useing the same weight oil, just brainstorming, it is also getting warmer outside which lower the viscosity of the oil, i could tell the difference in my car

 

[Chris Kennedy]

You will see MAJOR differences in oil pressure given the weight of oil you use. This is something that is never explained when people say "...you should be seeing XYZ oil pressure". One thing that is constant is, in my experience, that once you are at about 2000 rpm that is the maximum pressure you will see--I suspect that is why the various GM manuals talk about an oil pressure for our 350s being about 40 at 2000. I have used many weights, and also synthetic and conventional oil, and this is what I have found: Heavier oils (e.g. 20/50) will show much higher pressures when cold (70-80) at idle, and when hot will run maybe 45 or so at about 2000 rpm. Maybe more. Currently, I use Red Line Synthetic 5 W 40. It runs about 45-50 cold at idle, and when hot about 35-45 at 2000 rpm. I think your pressure is o.k., but if you want to increase it for a little extra piece of mind I would advise to use a 10/40 or 15/50 weight oil, regular or synthetic.


--Chris Kennedy
Houston, Texas

 

[magnesium]

Ive put 20/50... back to 40 at 2000 rpm... thanks!!!