Oil pressure wavering

[TxBoss23]

I noticed today while idling in line getting some food that the oil pressure gauge wavers between 50 and 60 PSI. When driving it stays steady at 65. Is this an issue? If so, what might it mean? The engine runs very well though it can be a little hard to start. 71 351 4v with Edlebrock intake and carb.

 

[kidwithfastback=fast]

Perhaps your oil pump could be failing. You could check that if you want. Is your idle steady?

 

[TxBoss23]

Yes, it idles smoothly at 900 rpm when warmed up.

 

[JimNiki]

The new pertronix 111 dizzy will retard the timing while you crank if that is the cause of being hard to start...

How worn is the motor?

 

[Mesozoic]

50-60 psi at idle is pretty high for a warmed up motor with hot oil flowing through it. I wouldn't be worried about that level of pressure one bit, though. If you could trust the gauge completely, it could be an indication of excessive oil clearance in a bearing somewhere. Time will tell...

 

[Jeff73Mach1]

I would consider the factory gauges as little better than idiot lights. If an aftermarket gauge, then it might indicate "something" if nothing more than the sensor reading a surge from the rotors in the pump.

50PSI at a 900 rpm idle is much more than you need to maintain proper lubrication levels. 10 psi per 1000 rpm is often tossed around as proper minimum pressure levels, though I never would want to see just 10 PSI

 

[TommyK]

Bad sender?

 

[Kermit 460]

I"ve seen a v8 car w/ mechanical gauges waver at idle when the oil level was a tad low .

 

[Mesozoic]

I would consider the factory gauges as little better than idiot lights. If an aftermarket gauge, then it might indicate "something" if nothing more than the sensor reading a surge from the rotors in the pump.

50PSI at a 900 rpm idle is much more than you need to maintain proper lubrication levels. 10 psi per 1000 rpm is often tossed around as proper minimum pressure levels, though I never would want to see just 10 PSI

Hey, I see about 10 psi at low idle in my Bronco's 400M... but it seems to run great. Even at 3000 RPM I don't think I see any more than about 40 psi when it's hot! That being said, when it was fresh it never read below 40 psi at idle and running it was always around 50-60 psi. I've obviously worn down the bearings, but I seem to have put an end to any further wear and tear by installing an engine oil and transmission fluid cooler since moving back to Arizona. I think it's the heat that kills the bearings.