S-10 Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I just picked up a engine for my 1997 Blazer at a local junk yard and got it running today. I noticed after starting it that the oil pressure was at 20 pounds and as the engine got warmer went to zero. I pulled the oil sender out and put in a gauge and still had no oil pressure. I removed the front diff and dropped the oil pan to find a new oil pump,pick up tube and all of the rods numbered and the rest looked clean and new. I'm kind of stump that it has a new oil pump and bearings but no oil pressure! The only other thing I can think of is if it got new cam bearings and the were put in wrong. Does any one else have any input on this. Ed
 

·
I'm slap happy, bitches!
Joined
·
2,178 Posts
or they put bearings on a worn out crank. you have the pan off now, plastigage a main and a rod, and see if its in spec.
 

·
Age: 15 1/2
Joined
·
2,679 Posts
Pull the dizzy and make sure you get the oil pump bar to slide in correctly???
 

·
Registered
Joined
·
8 Posts
Discussion Starter #5
I checked the crank with plastigage and it is within spec,so now i'm stumped. I will put another oil pump in and see what happens.
 

·
goin broke but n style
Joined
·
12,942 Posts
i would put an oil primer rod on the oil pump and spin it with drill. check you guage and see what the press is.

Maybe as stated the dist was put in wrong and damage the oiul pump rod or even bad dist.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
Ok I found the problom,the oil pump in the engine was a standard volume pump. The pump that comes in the engine from GM is part #93442037 and is a high volume pump,I installed a melling 155HV pump in the engine. I have 40 pounds when cold and 20 pounds when it warms up with 5W30 in it. Ed
 

·
goin broke but n style
Joined
·
12,942 Posts
if it has high mileage than i would go up to a 10-40 oil or a 20-50 oil. it will help on the oil press side
 

·
Age: 15 1/2
Joined
·
2,679 Posts
^^^What he said. It will also help with cylinder ring blow by.
 

·
I'm slap happy, bitches!
Joined
·
2,178 Posts
if the bearings look good, and your pressure does that, then my guess is cam bearings are worn out. an HV pump and thicker oil will help, but for how long?
 

·
goin broke but n style
Joined
·
12,942 Posts
i was also thinking how much damage has already been done. Try some 90 wt just for giggles and see what happens. That is a good old used car dealer trick.
 

·
"factory freak"...
Joined
·
8,601 Posts
using thicker oil to "improve" oil pressure doesnt quite work as well as it seems to....

the oil pressure is indeed higher leaving the pump, and by the sender, because the thicker oil is more difficult to pump through the passages.

but after making its way through all the pressure dopping bends and turns, past the cam bearings, into the mains, through the crank, to the rod bearings, the thicker oil ends up losing more pressure than the thinner, more freely flowing oil does.....

something to think about...
 

·
Registered
Joined
·
752 Posts
using thicker oil to "improve" oil pressure doesnt quite work as well as it seems to....

the oil pressure is indeed higher leaving the pump, and by the sender, because the thicker oil is more difficult to pump through the passages.

but after making its way through all the pressure dopping bends and turns, past the cam bearings, into the mains, through the crank, to the rod bearings, the thicker oil ends up losing more pressure than the thinner, more freely flowing oil does.....

something to think about...
nahhhh
 

·
"factory freak"...
Joined
·
8,601 Posts
perhaps you`d care to offer a more elaborate counterpoint???
 

·
Registered
Joined
·
2,685 Posts
My truck gets about 12psi when completely warm and low idle like 500rpm its an oldschool 350 sbc like an early 70's 350 and it runs great never had any problems,If you have 10 psi for every 1000 rpm then youre ok.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #16
These are the spec's for the 4.3 engine per GM Document ID# 62916. Ed

Oil Pressure (Minimum Hot)
6.0 psig at 1,000 engine rpm
18.0 psig at 2,000 engine rpm
24.0 psig at 4,000 enigne rpm
 

·
I'm slap happy, bitches!
Joined
·
2,178 Posts
meh, thats a myth, kinda.... the pressure is higher do to the lack of pumpabilty, meaning that the amount of oil going to the bearings is less.
 

·
Registered
Joined
·
353 Posts
musclecars Do you have any info on the 2.2 4 banger my ride has 121000 miles and when warm in gear its a automatic it has about 8-10 pounds of oil pressure and at cruise speed 2000-2300 rpms it will stay at about 20 pounds and it goes up as the rpms go up .I don't know just seem low to me but it seems to run fine . Just wondering? Thanks
 
1 - 20 of 21 Posts
Top