High oil presure

[Goat1314]

1989 4.3L 262 Mercruiser V6 2 barel

SO I installed a new head on my engine, put everything back together. Took it our for a spin and my Oil Presure is 6opsi at idle and goes up to about 75 or 80 at 3000rpm. THis is much higher then the Manual#7 says it should be

THey specify no less then 4psi at idle and no more then 45 to 55 at 2000rpm

I put new plugs In it
Tested the compression at over 150psi on all pistons
Droped a can of Seaform in the oil

Yesterday a cuople of times the pressure at idle after planing would drop to 40psi and bounce around then go back to 60psi

My question is how worried should I be. do I let the Seaform do its bit for a while... DO I pull the engine out and rip apart the oil pump... Is it just some crap in there that will work itself out eventualy??

Is such a high oil pressure uncommon anybody else out there run the same engine and what is your oil PSI at ??

Thanks guys

 

[Goat1314]

Re: High oil presure

Also I should mention that I cracked the head because the engine overheated and I had water in my oil that made a milkshake.I have since put a new oil filter and changed the oil (obviously) should I change the oil again??? What about dropping the oil from 25W40 to 10W30 or 5W20?? would that help to clean out the engine?

 

[04fxdwgi]

Re: High oil presure

Some causes of oil pressure jumping up:
1. Most probably (since you stated it dropped, then bounced up again): Stuck relief valve in oil pump (could have crud in there making it stick)
2. Bad sender
3. Spun cam bearing / plugged oil passage
4. Oil too thick

Change oil / filter again with high detergent oil of a lighter weight, run it for a while and change oil / filter again and see what happens.

Have done this before and added a pint of transmission fluid (which is has extremely high detergent content) to the oil. Run till warmed up, then change oil. Really cleans the engine insides.

 

[Goat1314]

Re: High oil presure

So I tried the Seafoam detergent and changed the Oil to 10W30

I've noticed that At low RPM like when I'm trolling we get a little blue smoke. Almost like I'm burning OIL. I'm keeping a close Eye on the Oil level of course. could the lighter oil be the culprit. Are Marine engine just a looser fit on the O-rings... is that why they use a thicker Oil (25W40) It didn't help much with the oil presure. That's down to 70 PSI at high RPM and 40 to 60 at low RPM.