worn out oil pump?
11-11-2001, 04:27 PM
#1
Melting Slicks
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worn out oil pump?
my LS5 puts out low oil pressure, only 25 psi at 2000 rpm, where it should be at 40 psi. i pulled the pump out yesterday and opened it up. i measured .006-.007 end clearance between the gears and the lid. is that too much? would that cause the low pressures i have?
also, can someone explain the operation of the bypass valve? how do i check it's condition?
thanks.
also, can someone explain the operation of the bypass valve? how do i check it's condition?
thanks.
11-11-2001, 04:52 PM
#2
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Re: worn out oil pump? (Turbo-Jet)
You can probably take the pump to and automotive machine shop and have the pump bypass tested, I think they check the spring pressure to do the test. If you are really worried about it you should probably just bite the bullet and replace it.
If the pump is good condition, the bypass is working correctly then low oil pressure is a sign of a generally worn engine. Sometimes worn cam bearings are the culprit in a low oil pressure scenario. The oil pressure you have is also a function of the viscosity of the oil. If you are running 5w-30 in a well warmed up car then 25psig isn't surprising.
If the pump is good condition, the bypass is working correctly then low oil pressure is a sign of a generally worn engine. Sometimes worn cam bearings are the culprit in a low oil pressure scenario. The oil pressure you have is also a function of the viscosity of the oil. If you are running 5w-30 in a well warmed up car then 25psig isn't surprising.
11-11-2001, 06:15 PM
#3
Safety Car
Re: worn out oil pump? (Turbo-Jet)
Cam:
I agree with with Steve. Why chance spinning a bearing or ruining your engine over an oil pump. I would probably shell out the extra couple bucks and get a new one. What is your oil pressure normally like with your big block?
I agree with with Steve. Why chance spinning a bearing or ruining your engine over an oil pump. I would probably shell out the extra couple bucks and get a new one. What is your oil pressure normally like with your big block?
11-11-2001, 06:27 PM
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Re: worn out oil pump? (Turbo-Jet)
How did you check your oil pressure? If it was with the oil gauge in the instrument cluster, use a second instrument to check what it really is. My oil gauge was reading 0 at idle with the engine warm. The gauge was reading over 30 psi too low....
As far as I know low oil pressure indicates worn main bearings.
As far as I know low oil pressure indicates worn main bearings.
11-12-2001, 04:18 PM
#6
Melting Slicks
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Re: worn out oil pump? (drives61)
Cam
.0025-.003" according to Smokey Yunicks POWER SECRETS
.0025-.003" according to Smokey Yunicks POWER SECRETS
i measured the pressure by connecting a proper mechanical gauge with 1/4" tubing to the sender port and plotted the results against rpm from a digital tach. the results were accurate to 1 psi.
thanks a lot. :cool:
[Modified by Turbo-Jet, 12:22 PM 11/12/2001]
