Taubr Unit

iTrader: (32)

We just did a ls6 swap in my buddys silverado because his 5.3 lost all oil pressure. Bought a ls6 crate motor from SDPP and still the same damn thing!! Heres whats goin on.... Inital start up was ticking but new motor, no oil etc so thats normal. After about 10 seconds of idle the oil pressure drops to 0, low oil pressure light comes on an motor starts to tick real bad so we have to kill it. WTF, brand new long block doing the same thing the old 5.3! Any advise?!

JasonSS2000

iTrader: (1)

Did you swap the oil pickup & pan from the 5.3? Sounds like the oil pump or pickup O-ring. Before starting a new motor always leave the plugs out, coil paks unplugged, and the fulel pump fuse pulled and then crank it until you have good oil pressure. Only way to properly prime a LS based motor.

On the relation to the 5.3 loosing oil pressure it would be impossible for the new motor to have the same problem uless you have an obstruction or failure or leak between the pick-up and the pump itsself.

You did use a new oil pump, correct?

MYSTIC-1SC

iTrader: (14)

thats what i was thinking possibly an o-ring issue.

Taubr Unit

iTrader: (32)

Yes we did have to use the truck pan and pick up tube. We had both motors on stands and really took our time and made sure the o ring was good. Cleaned the pick up tube really good etc. The oil pump was installed by gm n we didnt touch it, not sayin it cant be the problem, just sayin

89 formula350

iTrader: (8)

does this truck have the oil cooler?

G Engines

was all of the oil plugs and T-bar installed ?

Taubr Unit

iTrader: (32)

ok, truck does not have a oil cooler and we did not ***. the engine, its from GM. We did however make a little head room....

got a tip to pull the plugs n disconnect the coils and turn the motor over so its free reving pretty fast and that will "bleed" out the oiling system. So we did that and it got better but still not where it should be. At start up it bumps to 40psi then bleeds down to 20 and goes as low at 10 but not 0 now. Still not great but it did get better. We bought this motor from SDPP from the sale they had going on here. Was a complete long block. We did NOT remove the front or rear cover when we got it, just swapped out the oil pan n pick-up tube...the rest is gm

performinnorman

iTrader: (7)

Sounds like they might have left out either the front oil galley plug or the "barbell" plug in the rear oil galley above the filter.

89 formula350

iTrader: (8)

i thought there was issues with oil pumps and sticking valves in them? even later ones gm had tsb on them

orangeapeel

iTrader: (18)

Do you know what years the service bulletin was for?

89 formula350

iTrader: (8)

sorry i dont remeber i belive the early ls1's and ls6's were just random and no tsb was issued but the later '07?? ish trucks had this for sure... I used to work at a dealer and this was seen on a few trucks...

JasonSS2000

iTrader: (1)

Would have to agree. That or the O-ring got pinched.