first off, thanks for those that take the time to read this and
Im the owner (not builder ) of a 91 S-10 blazer that was converted
from a 4.3L to a 5.7L 350 engine. Im pulling the pan tomorrow to
change out the oil pump to a high volume one because the oil pressure
at startup is about 20-35 lbs at idle and drops to about 10lbs after
warm. 2k rpm is about 25 lbs pressure again. This is going to be an
all day job because of all the stuff in the way of getting the pan
Ok, can someone please tell me whats going on here. I rev up the
engine, and then right when i let off the accellerator the oil
pressure will jump up about 5 pounds. any clues to whats causing this?
THanks Again -Eric White
If it jumps up and not down when you let off the gas, it's loose main
bearings. Or at least it could be. Did you put a real oil pressure gauge on
it or are you reading the stock gauge? Before you pull anything apart be
sure to check it with a real gauge.
I agree, a bigger oil pump is not going to fix worn bearings. A 350
has a fine stock oiling system by design and it fails only from
neglect or abuse (and it takes a lot of abuse too). Replace the main
and rod bearings and forget the oil pump if you really want it to last
for a while.
Thanks to all the helpers. I ended up replacint the stock pump with a
high volume one and used 30wt castrol oil. pressure is now 40 at 2k
rpm and 20-25 at idle. It too litterally 12 hrs to replace this pump
because of all the shit that had to be removed, engine mounts removed,
engine jacked up and misc other issues just to get the pan to release.
To top it all off, now i have a gasket leak in the pan......sigh......
Thanks gang -eric
i know i know, its not a fix to the problem but only a band-aid. I
bought the truck as a quick fix to needing a vehicle to drive for my
delivery route. I really do not intend on keeping the truck more than
a few months so i can save back a little cash to buy another in far
better condition. This is a whole lot more power than i care for or
need but it runs good, sounds good, doesnt burn oil or leak any now -
remote oil unit was the culprit. I was seaking info to make a decision
on keep the vehicle and rebuild the engine, or drive as is ans sell.
Im going to sell if its still in 1 piece in 5 months.
THanks again -Eric
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