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50 high oil prressure

S

skinut

Member
"Recently bought an '04 Gl

"Recently bought an '04 Glastron w/5.0 carb. Mercruiser/Alpha 1 with 40 hrs. on it. Only driven to fishin hole on Sunday by a little ole man. Changed all fluids. Oil pressure is at dead center (40 psi) at idle and moves up to 60 at 3000 rpm and on up to 80 psi ( pegged out ) at 4000 rpm+. The oil level is a little above full mark (1/4") Is this going to hurt anything or do I need to drain oil down to even full and see if anything changes. When I changed it,I drained from bottom and added required amount. Will the 80 psi blow anything? Thanks-This site is a blessing!"
 
"It's doubtful your oil pr

"It's doubtful your oil pressure is actually that high, assuming your oil relief bypass is not plugged, and it is hard to imagine that happening. I would have your oil pressure sender and gauge checked, or consider replacing your sender.
Rod"
 
Thanks for the reply Rod!! I j

Thanks for the reply Rod!! I just don't want to blow any gaskets or anything. It only pegs out when it is really wound up and backs off quickly when the throttle is pulled back a little. I used the Merc 25W40 oil.
Thanks Again.
Marty
 
"With Merc 25W40, you should t

"With Merc 25W40, you should typically have an idle oil pressure of perhaps 15-20 psi, and a max at WOT of maybe 50 psi. That's with the oil fully warmed up. So I think your sender or gauge is reading high right across the board. The relief is typically set at about 60 psi, so you would not normally see any pressure above that. Not that a somewhat high oil pressure is detrimental to your engine. Higher oil pressure is certainly much better than too low. You could verify all this if in doubt by substituting a direct reading pressure gauge for sender unit.
Rod"
 
"After verifing that the gage

"After verifing that the gage is accurate, which it might not be, I'd switch to a 10W30 oil.

Jeff"
 
"Thanks Guys- I will check the

"Thanks Guys- I will check the pressure with a direct reading guage. About the oil, I know this is the "million dollar question" but is Mobil 1-10W30 about as good of an oil as can be bought for this engine or is the Merc oil the one to stick with. Price is not a factor considering I will only change it once a year in the fall after boating season is over. I want the best oil available!!
Also,does Wix or Napa or another top of the line filter company make a filter for this engine that is as good or better (or the same)than a Merc. I have to drive 3 hours to get Merc oil and filters. Thanks"
 
"You won't go wrong with M

"You won't go wrong with Mobil 1. After you confirm what your actual oil pressure is, you can decide 10W-30 or higher visc.
For filters, I understand NAPA have crossover numbers for Merc PN's. Never checked it out myself.
Rod"
 
Thanks Rod- You have been a gr

Thanks Rod- You have been a great help and I really appreciate it. Have a great day!
Marty}}
 
"I have found NAPA stores in c

"I have found NAPA stores in concentrated boating areas carry many marine parts; carter fuel pumps, oil and fuel filters, misc. items."
 
Thanks Guy- I will get my Merc

Thanks Guy- I will get my Merc part # and check with my local NAPA store. I am sure someone makes them for Merc anyway.
Marty
 
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