Fookster

iTrader: (8)

Alright here's the deal I work for MAPerformance and we put my engine together a few weeks ago(Evo VIII):

-JE Pistons(out of a crankwalked 2g with hardly any miles on them, block was bored to these pistons)
-JE Piston Rings(Brand New)
-Cometic Head Gasket(Head Decked)
-Eagle Rods
-BC 280's
-BC Springs
-Supertech Valve Seals

I'm running AEM and we tuned it the other night and now after a pull it smokes hard core oil smoke on decel and only on decel. During the pull and during regular(no boost) driving there is no smoke. We don't think it's the turbo(stock) because there is no shaft play and why would it only smoke on decel.

Anyone have any ideas?

Fookster

iTrader: (8)

Compression test: Good across the board

Curt@MrLed

iTrader: (107)

You may have a oil land ring problem, or bad valve seal, or turbo seal. The reason for smoke on decel is vacuum.

Watch your plugs, and watch the turbo inlet for leaks. youll find it soon.

I would be suspect of the rebuild.

Fookster

iTrader: (8)

Rebuild was done by Kyle here at the shop. He's done a million motor builds along with making 709hp on his Talon and running a 9.

Thanks for the reply!

Fookster

iTrader: (8)

Also Plugs looked very clean. Not like plugs after burning oil...

Benja

Doesn't mean it isn't the rebuild, especially considering you didn't use new pistons...

Anyway, did you check the stem seals in the head? They pull oil into the combustion chamber when leaky and produce oil smoke on back-off.

dubbleugly01

iTrader: (24)

sounds like a valve stem seal is leaking.

Fookster

iTrader: (8)

Hope it is and not piston rings.

Benja

Perform a leakdown test.
That will give you a pretty good start to where the problem lies.

TheEvolutioner

iTrader: (12)

Why would it be the valve stem if he checked the compression and its good for all cylinders? Sorry for the newb question, just trying to understand.

nothere

iTrader: (23)

listen at the tail pipe or the intake.

looks like you are that person that shxt happens too. to bad, you got bad karma?

Curt@MrLed

iTrader: (107)

Like I know who that is.
Things happen, people make mistakes.

thebluesky

iTrader: (28)

WHy do you think those pistons would have anything to do with this? If they were bad, there would be other symptoms other than just smoking on decel.

Chris@nolimitmotors

iTrader: (277)

Evo 8 valve pockets are opposite of 2nd gen pistons, not sure if thats your problem but im sure it cant be helping.

dubbleugly01

iTrader: (24)

when you check compression, the valves are closed, so a leaking stem seal won't show up. But under decel, the intake manifold and cylinder itself see vacuum, sucking oil past the valve stem seal if it's bad, and into the combustion chamber.