[TJ SKWIG]

so i dropped in a supposedly fresh rebuilt 350, when cold it runs at about 50 psi oil pressure, as it warms up, it starts to drop off.. which is expected i know, but when at 180 degrees and at idle, its almost at zero.. if i hit the gas, it will jump up quickly, to around 25-30 psi which is almost okay in my book, the real problem is that when at cruising speed, 40mph it is intermittently dropping oil pressure, it will be at 30-40 psi one second, then it will drop out for anywhere from 2 to 10 seconds... then recover... like the oil isnt getting back down to the pan fast enough... i pulled the engine back out to check bearings, oil pump etc.. i cut the oil filter apart to see if it had a bunch of crap in it.. had some, but didnt seem like enough to worry about... it has a melling high volume pump on it, not sure of age... and the bearings still look okay... they are .020 bearings... im kind of at a loss at this point.. any ideas? all i can think of is to maybe try another oil pump, but dont really want to spend the money on one if i dont need to.. or throw it all back together and throw some more oil and new filter on it and see what happens...????

 

[wave_crusher]

it's probably just the gague itself, you really can't trust a stock oil pressure gague, which is why you see a lot of after market oil pressure gagues on built vehicles

my OPG jumps up and down from time to time, it was stuck at 10 psi for a while so I took it in to the college auto shop and it read at like 60 psi or whatever it was supposed to be at, all the while the stock gague said 10 psi.

my adivce, stick a new filter and oil in it and get an aftermarket OPG

 

[Kodiak450r]

i'd get rid of that high volume oil pump. on a stock engine there is no need for something like that. if it's a stock build then they probably didn't open up the oil drains in the heads and block to allow oil to flow back to the pan quick enough. the other thing i'd do as previously stated is mechanically check your pressure with a handheld gauge.

 

[sbcrichie]

another thing to check is the clearance between the pickup and the bottom of the pan.

 

[whyme86]

sounds like a gauge put another gauge non electric and see where your pressure is at also what oil are you running? What does your cam bearings look like check and see if all of your oiling holes are right where they are suppose to be in the cam valley.

 

[TJ SKWIG]

it has an aftermarket guage, and i can hear the chatter when it goes low on oil.. definitely not the guage, and its not a totally stock rebuild... its got a few aftermarket parts in it... and i checked the clearance to the pan on the pickup and it seems okay.. sits right at the bottom of the pan.. i was thinking of getting a higher volume pan...??? so it doesnt run low on oil as easy...

 

[Yetti]

I wonder? cam bearings can be the culprit if your chasing a ghost oil pressure issue. they tend to bleed out bad if they are cocked in the bores. if you want bring it by and we'll hook up a test gauge and see whats up. you remember where I live?

 

[TJ SKWIG]

I wonder? cam bearings can be the culprit if your chasing a ghost oil pressure issue. they tend to bleed out bad if they are cocked in the bores. if you want bring it by and we'll hook up a test gauge and see whats up. you remember where I live?

yeah i remember where ya are... although the engine is no longer in the car, i have it torn down to the shortblock right now to eyeball everything... something i should have done when i bought the engine... but after inspecting this thing, im sure its a fresh rebuild.. but i might just go ahead and throw a new pump in it, just for the re-assurance that the pump is ok, maybe ill pull the cam and check that out too... the dipstick that is on the motor is a bit suspect too.. its a fancy lokar one that was on it when i got it... i filled it to what said full on the dipstick not knowing the capacity of the aftermarket oil pan, and i think it may have been overfilled now, possibly causing the oil to become frothy and throwing the OPG off...