overhere

iTrader: (2)

long story short had a lq9 cam only, after many years of abuse melted a piston. ran 9.10 @ 132, normally trapped 152.

swapped in a 5.3l had it running for a few weeks and on the third time to the track about 8 pass car shut off right before the stripe. got it to run about a minute noticed it only had 15psi oil pressure at idle. use to has about 45psi. shut it off then couldn't get to start found out blew the fuse to the msd. did a compression test about 125psi across all. fired it back up runs but very low oil pressure. rev it and pressure does go back up a little ways.

my question is what are some of the reasons that i would loose oil pressure? at cold idle only have about 20psi and the drops down to about 10-15 hot. i was thinking i spun a bearing or something but the engine doesn't sound bad?

AutomagicLS1

iTrader: (18)

cut the filter

overhere

iTrader: (2)

with out a filter cutter whats the best way to? last time i tried i end'd up with more shaving from the saw then any thing else.

AutomagicLS1

iTrader: (18)

most autoshops or performance shops should have one. If not I think they are like $30 through speedway motors

a4ls2goat

My 5.3 sees about 15psi of oil pressure at idle hot (800rpm) at 100+ degrees ambient.
75psi at 6k rpm wot.

Also, what oil weight do you use?

overhere

iTrader: (2)

well i just used a die grinder and cut the top off. there is some flakes in it and the oil also had some slightly looked like metal flake pretty sure i was right and spun a bearing.



i used 5w30 but untill after the strip was the first time the oil pressure has been that low. and started it agian today and its still low. like i said it use to be around 45 cold now its 15.

AutomagicLS1

iTrader: (18)

When I cracked a callies crank and it took out a rod bearing this is what was in my filter. The bearing wasn't down to the copper yet either.

overhere

iTrader: (2)

yeah mine dosn't even look that bad but there are definitely flakes floating around and i dont want it going threw the turbo anymore then what already has.

2000RATA

Yep you are done. Better finding it now rather than when it scatters.

overhere

iTrader: (2)

here is a pic of the lq9 piston.

conan

iTrader: (5)

^^^

Well done sir...

Is the 5.3L knocking ? I had the same thing happen to my LM7. New oil pump was all it needed... 225,xxx on the clock.

overhere

iTrader: (2)

it dosn't make any noise at all. if i didn't have an oil pressure gauge i would still be running it. besides all the little shiny piece's in the oil. oil pump has probably 500 miles on it.

9sectruck

iTrader: (9)

my factory ls2 oil pump relief valve stuck on me destroying the engine, check that first but if there is shavings in the oil Id say its done