Ok heres the setup:

2003 Avalanche 5.3 v8 w/Livernois Turbo System 7.5lbs of boost

I am getting smoke (from Oil cause it's blue/white and smells like burned oil) out the exhaust after the truck has run for about 15 minutes (up to operating temps). Now, i though it may be the Turbo bushings since its a little over a year old but, i am getting the smoke out the Breathers on the Valve cover too (passenger side with the Turbo oil return)! This leads me think either the Rings are going or the head is damaged.... No loss in power (yet) and i have been driving it like this since Saturday and the oil level seem to be fine so, its not a Huge amount being burned...

Any ideas guys? I know i am heading towards a new motor regaurdless...

 

Well you have the tranny to hold any engine, so I say the 5.3 is done. Get a 402 or 408.

Really though, do a compression check and look at your plugs. Sounds like your rings may be going. or gone.

 

Sounds like to me you've got a good bit of blow-by and it's time to freshen it up.

 

I don't what i want to do... and yes, i am glad i have the transmission there already... i really can not afford an all out 402, would be happy just boring out the 5.3 to like a 5.7 or 6.0 with some nice heads and cam. as long as it's stroked and forged so it can take the boost. I have got tons of room for boost with my turbo and i don't race so, i want good streetable power. i just have to do some research on whats out there and decide what i want...

 

If your block is in good shape, you could bore it to 5.7 like you were saying and get a good strong rotating assy., do a little headwork, pick a boost cam out, and turn up the boost some.

 

i dont get how the engine is giving out with only 7.5psi. It should hold 12-15 stock for along time.

 

I don't think stock GM motors are built to the highest tolences. LoL
But you are right, my buddy runs 12lbs +100shot on his stock 5.3 and he is still running strong for th past 6 months... for the moment... I have been boosted for just about 1.5 years...

I am leaning towards rebuilding to a 350 (5.7) just for the costs savings...

 

exhaust valve seals?

 

Could be the valve stem seals also. If your gonna swap motors, do a forged 5.7 or 6.0. Either one with 12 psi and a good tune with a stock cam and 6.0 heads will make about 600 rwhp and drive like it is bone stock. That is until you get on it.

 

thats not much boost...check your valve stem seals and compression test...maybe just be something simple like that...