2007 6.2 Denali 230k smoke on start up

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ls1frc

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What color?

If it's blue and goes away, it's oil and probably valve seals.
 

blackelky

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If you fix it. Might as well do a cam and valve job while you're at. I personally would run it until it dies with the mileage.
 

j91z28d1

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change valve guide seals and add a catch can. should help
 

petethepug

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Wow! Lotta high milage 07/08 Denali / 6.2L posts this week. It’s homage to the LS motors giving 2-300k in milage.

With that oil consumption waiving a flag for valve seals it’s kinda thrown a flag for a 50k ~ miles left warning. Waiting for bearing failure due to a poss unforeseen low oil sitch isn’t good because these 6.2 cores are worth big $ these days.

Just saw an episode on PowerBlock of an early normally aspirated CTS-V swap. They swap’d (what they thought was) a 400hp 5.7L to a 6.0L 2500 / 3500 iron block alum head 380hp motor. They took the 6.0L truck motor, added new aftermarket alum heads, a cam, headers and everything thing else stock.

After the tune, on the same ECU, the n/a motor made 507 hp. Just say’n, salvage the 6.2L before it grenades. Start shopping for new heads, cam & headers now.

Have a plan to pull the L92, have it machine serviced as a short block. Save $ on machining heads and get new aftermarket alum heads, cam & headers. Get it tuned and have budget 500hp budget rebuild. Milage will go up because the motor’s not going to lift a finger anymore pulling that AWD XL Denali around at 1500 rpm.
 

Joseph Garcia

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Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

I suggest putting an oil catch can on it first and see if the smoke goes away.
 

donjetman

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