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Losing Oil Pressure?

Old 07-21-2004, 12:32 PM
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Default Re: Losing Oil Pressure?

Cut the filter to see if anything came apart in the engine. Also, are both
engines oil level the same after sitting and after running???

Mike
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Old 07-21-2004, 12:36 PM
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Default Re: Losing Oil Pressure?

I will check the filter and yes both oil levels are the same. oil looks very clean I hope I didnt wipe out a new set of bearings again.
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Old 07-21-2004, 01:14 PM
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Default Re: Losing Oil Pressure?

35-40 lbs is that running or at idle, cold or warm? If that's what you get when you throttle up a fairly cool engine, that's low to begin with.
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Old 07-21-2004, 01:27 PM
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Default Re: Losing Oil Pressure?

I get around 30 psi at cold idle and 40 psi running back to 35 warmed up at idle. remeber a fairly stock motor . what should oil pressure be?
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Old 07-21-2004, 01:45 PM
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Default Re: Losing Oil Pressure?

With a $35.00 Melling hv pump I get 80 cold 1000 rpm, 50 warm idle, 60 at 4000 steady for an hour. I know some Mercruiser lo po engines only run about 45 but yours is worse. It would seem that your bearing clearances are wide enough to allow all of that oil to just flow through once it warms up.
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Old 07-21-2004, 01:54 PM
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Default Re: Losing Oil Pressure?

Maybe I should get the Melling pump this time around. Maybe the bypass valve is stuck open or there is something stuck in it? I need to check that this weekend.
Thanks for the replies.
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Old 07-21-2004, 03:53 PM
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Default Re: Losing Oil Pressure?

Originally Posted by Big Dawg
Gary I did not replace the cam bearings. but the engine ran perfect for 2-3 hours before losing oil pressure. why would the bypass fail after so long?
If you did not hot tank the block, buy a new cooler and thoroughly clean all other parts after the first bearing failure, you are now circulating metal from that failure. This metal quickly creates more metal from the new bearings. I assume since you did not replace cam bearings the block was not hot tanked. This is most likely the cause of the problem you have now. I hope it is not, but cutting the filter open now is your next step.

BT
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Old 07-21-2004, 04:12 PM
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Default Re: Losing Oil Pressure?

You are all wrong, dang it. DETONATION is your problem, will pound out main and rods in 45 min'. I bet you have a ton of metal in your oil filter.
Answer = Distributor curve is incorrect. junk dist, buy new and retool engine 1 more time. Good view of old bearrings would have told you detonation. You pounded the bearings to death then oil pressure goes to 5 psi.
Been there, done that. I had the exact results you are having, sorry dude.
Kurt

P/S you can not hear Detonation with water cooled exhaust. like a automobile cheap gas ping . must get total timming, not base. My junk distributor totaled out @ 1,200, way to low for marine severe duty appl', new distrib totaled @ 2,200 rpm. Big differance.
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Old 07-21-2004, 04:32 PM
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Default Re: Losing Oil Pressure?

Originally Posted by Mr. Bravo III
You are all wrong, dang it. DETONATION is your problem, will pound out main and rods in 45 min'. I bet you have a ton of metal in your oil filter.
Answer = Distributor curve is incorrect. junk dist, buy new and retool engine 1 more time. Good view of old bearrings would have told you detonation. You pounded the bearings to death then oil pressure goes to 5 psi.
Been there, done that. I had the exact results you are having, sorry dude.
Kurt

P/S you can not hear Detonation with water cooled exhaust. like a automobile cheap gas ping . must get total timming, not base. My junk distributor totaled out @ 1,200, way to low for marine severe duty appl', new distrib totaled @ 2,200 rpm. Big differance.
Well you must have way more information than the rest of us. Detonation typically causes a myriad of other problems first.

BT
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Old 07-21-2004, 05:21 PM
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Default Re: Losing Oil Pressure?

BT, you missed some lines on my Quote. Upon viewing of old bearings would have told you DETONATION, I may be Wrong since i can't see this Granade in person. My 2 cents B3


P/S I thought this would eark someone with a pro mind such as BT, not my intentions.
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