5,7 Merc. Oil pressure question

vitali69

Cadet
Joined
Feb 2, 2008
Messages
15
Hi All
I have 5.7 Mercruiser 1995. On idle pressure of oil 32-33 Psi. 3200 RPM - 37 Psi. This pressure normal? Or I should change the Oil pump? Engine 350 hr.
Thanks for advice
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: 5,7 Merc. Oil pressure question

Yes - No. 10 PSI/1000 rpm is pretty normal for a small block Chevy.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 5,7 Merc. Oil pressure question

Is that the real oil pressure, or just what shows on your gauge?
 

vitali69

Cadet
Joined
Feb 2, 2008
Messages
15
Re: 5,7 Merc. Oil pressure question

This that that shows the gauge, ( it new)
 

fishmen111

Chief Petty Officer
Joined
Feb 1, 2008
Messages
637
Re: 5,7 Merc. Oil pressure question

I think you might need a new sender. 4psi difference between 850 and 3200rpm? I don't think so. Your 37psi is fine. Clogged sender, cheap fix.
 

vitali69

Cadet
Joined
Feb 2, 2008
Messages
15
Re: 5,7 Merc. Oil pressure question

But the last owner of a boat, has changed on new sender ,the half year ago
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: 5,7 Merc. Oil pressure question

Go to napa, autozone, get a $20 mechanical gauge, and test it.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 5,7 Merc. Oil pressure question

But the last owner of a boat, has changed on new sender ,the half year ago

Faulty gauge, sender, corroded wiring, all can cause a false reading. As Coors stated, get a mechanical gauge and find out what is really going on.
 

vitali69

Cadet
Joined
Feb 2, 2008
Messages
15
Re: 5,7 Merc. Oil pressure question

Thanks guys, I shall check up, I that I go next week in offshore.
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: 5,7 Merc. Oil pressure question

Offshore? you need a factory manual, and read it, first.
And take the spare parts you might need. And tools.
 
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