no oil pressure

m8kinulook

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May 7, 2007
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have a 00 stingray with 5.0 merc. efi 240hp with alpha 1. just picked boat up a week ago and ran it with muffs for 10 mins with no problems. well this weekend took it to the lake backed it off the trailer and started to head out when i noticed it started knocked when i tried to throttle it . then alarm went off and noticed no oil pressure. **** it off checked everything. restarted it and at idle its fine but no oil pressure so i tried once again to throttle it noticed it tried to jump up to 20psi but just didnt have any power and started knocking again so i brought it back to idle and loaded it up. now its time to figure out whats wrong. recently serviced at dealership so oil and filters are fine i so no leaks . my guess is oil pump or pick up tube. any thoughts?
 

Monte1961

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Re: no oil pessure

Re: no oil pessure

I would be looking further into it. IE: bearings.
 

searay3

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Re: no oil pessure

Re: no oil pessure

Did you actually check the dipstick? Mechanics have been known to make mistakes. If the level checks out, pull the drive and attach a mechanical oil pressure guage, crank it over for a few seconds, see of the knocking stops and if it shows oil pressure. Still knocking and no pressure? Pull the engine to disassemble and see what happened.
 

m8kinulook

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Re: no oil pessure

Re: no oil pessure

checked oil, everything is fine. but remember no knocking at idle .
 

Monte1961

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Re: no oil pessure

Re: no oil pessure

Just incase, you want to install a mechanical oil pressure gauge to verify what the oil pressure really is. And if it all possible, use one that is oil filled. Will be more accurate.
 

ryanr623

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Re: no oil pessure

Re: no oil pessure

Pray its your oil pump.

When my oil pressure dropped in my supra, the cause was rod/main bearings. You said no knock at idle but mine didnt either... rod knock is most predominately heard at 2000-2500 rpm.... or while feathering the throttle.

If its knocking and has oil, im gonna venture and say your rod bearings are bad.
 

m8kinulook

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Re: no oil pessure

Re: no oil pessure

Pray its your oil pump.

When my oil pressure dropped in my supra, the cause was rod/main bearings. You said no knock at idle but mine didnt either... rod knock is most predominately heard at 2000-2500 rpm.... or while feathering the throttle.

If its knocking and has oil, im gonna venture and say your rod bearings are bad.

ouch....got a oil filled mech gauge will be testing it tonight and going from there.
can anyone tell me how to read the codes on this boat or what scanner to use?
 

Monte1961

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Re: no oil pessure

Re: no oil pessure

Is all the oil sensor does is detect that there is oil pressure. The reality is, 12lbs oil pressure is all thats needed @ idle. However, check with gauge and let us know.
 

fixit12

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Nov 9, 2008
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Re: no oil pessure

Re: no oil pessure

From the sounds of things, your looking at pulling an engine. You saw 0 oil pressure too many times and heard knocking too many times to not have internal damage. Without a teardown and look see your problem won't change. It's not the thing you like to hear but..... keep us posted.
 

m8kinulook

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Re: no oil pessure

Re: no oil pessure

From the sounds of things, your looking at pulling an engine. You saw 0 oil pressure too many times and heard knocking too many times to not have internal damage. Without a teardown and look see your problem won't change. It's not the thing you like to hear but..... keep us posted.

will do thanks everyone ! ill keep yall updated!
 

searay3

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Re: no oil pessure

Re: no oil pessure

It would be bad if you pull the engine only to find out you had bad ujoints and a shaky electrical sensor...just sayin..
 

m8kinulook

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Re: no oil pessure

Re: no oil pessure

well its rod bearings....so now the question is do i buy a complete motor and just drop it in or rebuild this one...
 

Brewman61

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Re: no oil pessure

Re: no oil pessure

Your call. If it were me, I'd get estimates on both, and decide from there. Parts and labor on a rebuild vs a new(er) engine.
 

ryanr623

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Re: no oil pessure

Re: no oil pessure

well its rod bearings....so now the question is do i buy a complete motor and just drop it in or rebuild this one...

Sorry to hear, i figured thats what it was. I would buy a new engine (reman) personally. It was hell when my bearings went out. Its not just pulling the entire engine, is machine work to your crank that has to be done, down to minute tolerances and the bearings need to fit perfectly. Its a LOT of work.....and takes a LONG time. Annnnnd if the shop doesn't do it right, you're looking at it starting to knock again really soon. Happened to me, and my friend and we went to different shops.
 

Bondo

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Re: no oil pessure

Re: no oil pessure

well its rod bearings....so now the question is do i buy a complete motor and just drop it in or rebuild this one...

Ayuh,... That 1 is full of ground up bearings...

I'd go with a new long block myself...
 

m8kinulook

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Re: no oil pessure

Re: no oil pessure

so wheres the best places to find a replacment? and should i jump up from a 305 to a 350 being its efi? and if so will all my electronics work with the new 350?
 

Bondo

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Re: no oil pessure

Re: no oil pessure

so wheres the best places to find a replacment? and should i jump up from a 305 to a 350 being its efi? and if so will all my electronics work with the new 350?

Ayuh,... That's the Problem, it's Efi...

No boostin' the Power, without a new 'Puter...

If it were carbed, goin' with a 350 would be No Problem...
383 Stroker if ya wanted too...
 

m8kinulook

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Messages
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Re: no oil pessure

Re: no oil pessure

Ayuh,... That's the Problem, it's Efi...

No boostin' the Power, without a new 'Puter...

If it were carbed, goin' with a 350 would be No Problem...
383 Stroker if ya wanted too...

ah i was affraid of that...that sucks...so guess its remain/new 305 for me...
chime in someone on some good places to get a long block?
 
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