High oil pressure

littlebookworm

Chief Petty Officer
Joined
Nov 30, 2007
Messages
574
Hi, everyone. I'm finally just about ready to drop in my new-used engine into my boat. Engine is a 1983 Mercruier 5.0 with raw water cooling. Had to do a valve cleanup and lapping, but everything else was fine. I'm running it on a dolley at the moment with water hose connected. At idle, oil pressure is 30 lb. At 3000 RPM it goes up to 60-70 lb. I've checked with a mechanical guage and got the same readings. I've dropped the pan and the oil pump and checked the pressure relief valve. OK. I've changed the oil filter even though it was new. Oil is 30 weight. The engine does have a no-name aftermarket remote oil filter setup using a PH8A filter rather than a PH30 filter usually listed for that engine. The 8A does have a smaller mounting/flow surface than the 30. Could that be causing the high pressure? Is it something I should be concerned with? Thanks. Hy
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,476
Re: High oil pressure

That sounds ok to me especially if the engine is cold. What is the pressure when it is warm?
 

Windykid

Lieutenant Junior Grade
Joined
Apr 17, 2007
Messages
1,177
Re: High oil pressure

sounds good for fresh 30w and cold.;)
 

littlebookworm

Chief Petty Officer
Joined
Nov 30, 2007
Messages
574
Re: High oil pressure

I've let the engine warm up to approximately 130-140 on the guage and the numbers stay the same. My gut feeling was that they're OK but I wanted to check with you all. I know that an auto engine runs a lower pressure unless it's had a high-pressure pump installed, so I got a little nervous. Look forward to finally dropping the engine in. Thanks all, and safe boating. Hy
 

tie_one_on

Petty Officer 1st Class
Joined
Oct 27, 2003
Messages
276
Re: High oil pressure

A PH8A is a Ford filter. Take it off. Put a PH30 on and recheck.
 

littlebookworm

Chief Petty Officer
Joined
Nov 30, 2007
Messages
574
Re: High oil pressure

I thought of doing that, BUT, when I got the engine it had a PH8A on it. Comparing the PH30 and the PH8A, the diameter of the sealing O-ring on the 30 is larger than the 8A and will not seal aroung the base of the remote oil filter base. Any suggestion of a different number to use? Hy
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,506
Re: High oil pressure

Ayuh,....

I don't see any Problem.....
 

littlebookworm

Chief Petty Officer
Joined
Nov 30, 2007
Messages
574
Re: High oil pressure

Thanks, Bond-o. I was hoping you'd join in. That makes it official. Hy
 
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