Oil pressure 502mag, 433 hours

Hello All, after such good recommendations for my last problem, I had to try this again. After reading another post about oil pressure, I think I might have a problem. My oil pressure gauge always reads 40Psi and the only time it moves from that is during start up. I'm now thinking the only reason it moves is because of the electrical break in current when starting. What should the oil pressure be? Should it fluctuate (my 454 did)? This sounds like a stuck sending unit, I disconnected but nothing changed. Are there two of them? Where are they located? I won't have time to work on it for a few days. Will a car sending unit work as a replacement? Thanks again to All for the help, it's appreciated!

James,

San Diego

One would think that it would fluctuate with rpm changes and whether cold or hot.

Can you try a different gauge or an oil pressure tester?

ground the sender lead, the guage should peg. if it does the gauge is good.

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Originally Posted by phragle

ground the sender lead, the guage should peg. if it does the gauge is good.

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I did not know that. Always true?

I cant say always, but usually.

Yes that is how you check gauge circuits. The various senders read levels of ground and pegged is the most grounded. The only exceptions are tachometers do not ground sender lead. and some VDO s read backwards.

Wow, if I keep hanging around with you guys I may be smart someday!!!!!

We all need a Jim clone to go boating with.:)