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High oil PSI

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805HD

Regular Contributor
1987 cobalt 454 w/ alpha1


just replaced the engine with a new one (used). Engines in good shape, everything looked great. Real clean.

fired up and am getting 70+ psi oil at idle. Replaced the pressure sender, still high. Should I be overly concerned about this?
 
no....

If you don't know the history of your 'new' engine, the only thing you can do is look for change(s)....an oil analysis now would help you establish a reference...

If the oil you have in it has a 'high' viscosity rating, higher pressures are common, especially when cold.

I would be more concerned that the engine maintains pressure after running with a normal load for 30 minutes or more...
 
Yea, I’m running 15w-40

Haven’t had the boat out on the water yet just some run time on the hose with muffs. I agree, taking it out and letting it really warm up to full op temp you would hope to see a drop in oil press. Should tell me more.

I primed the engine prior to install. Definitely getting plenty of oil up to the rockers. I suppose higher is better than lower. But 70-80 psi at idle?! Crazy! Even if it’s just for 10-15 mins..
 
You don't need multi-vis since you aren't operating in sub freezing conditions. Straight SAE 30 is what I put in mine.
 
We used to see 80 PSI at startup with 15W-50 (M1) in the spring and fall...on those crisp mornings....after things warmed up 40 was expected...and 30 PSI was nominal pressure at idle on a hot summer evening hitting the fuel dock....
 
My suspicion is a slightly miss matched sender and gauge
If motor was rebuilt and this is first run, the tolerances could have been kept on the tight side on the journals or possibly a new oil pump with high out put. Maybe the relief valve is on the high side
 
Every engine should use multi-viscosity oils. Period! Greatest invention of all times for long engine life.

Jeff
 
Yea I’m not sure about the high volume oil pump. It’s a gen4 big block and does seem to have a larger pan on it.

anyways, won’t know till I’m on the water.
 
805HD said:
Yea I’m not sure about the high volume oil pump. It’s a gen4 big block and does seem to have a larger pan on it.

anyways, won’t know till I’m on the water.
Click to expand...

Quick silver 25/40 oil.... Everyone has their own opinion.... I run this in my Pro Street car with a Blown SBC....
 
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