jsttry

Have a problem with oil smoke and trying to find the source.

Pretty much standard LS1 with a Garrett T51R turbo running 7-12psi, has been in the current setup for nearly 12 months. Turbo is mounted on left hand side of vehicle and has oil lines to sump.
Runs fine under WOT
Slight lump to idle but could just be my tune
Problem is when deaccelerating after WOT it blows blue smoke. Also very prominent when doing right hand turns in city driving. Sometimes also blows small puffs at idle.

Replace both sets of valve stem seals, still the same.

Could it be something with the oil lines to the turbo having a restriction? Could it be turbo seal?

I would assume if it was a turbo seal or piston rings it would occur under WOT too.

Tainted

iTrader: (9)

blue smoke means yur burning oil and oil consumption is commong with an ls1 so start simple, check the pcv system

jsttry

always knew blue = oil but its never been like this before, have never had a problem with blue smoke.

don't have a PCV system on the Australian LS1

bczee

iTrader: (12)

Do a Leak Down Test, it is a good tool to find out the health and problem of your engine.

bigturboz28

I agree, check rings seals - leakdown test (assuming the PCV system has been setup properly for the last 12 months - or doesn't exist ).
Another possible source is the labyrinth seal in the turbo on the exhaust side, however it seems unlikely as it is only happening when you get off the throttle.

brad8266

iTrader: (23)

Blue oil on deceleration(closed throttle) is likely the oil seals on the valves. I would check those out and also be sure yo use thread sealant on the rocker bolts too.

jsttry

Will try the leak down test. Is that the same as a compression test?

Brad, already did both sets of valve stem seals.

brad8266

iTrader: (23)

Leakdown is kind of like a compression test except it will tell you the percentage of leakage and you will also find out where the leakage is coming from. Harbor Freight sells a leak down tester for like $40, it is a good tool to have.

jsttry

Checked the oil lines to the turbo just in case, no blockages there.
Did a compression test and it all came back normal.

Only thing the mechanic is now suggesting is a valve or valve guide which means heads have to come off. He's suggesting to do a head upgrade at the same time but am happy with the power and don't want to push it further with a stock bottom end.

If the heads are off and the valves and guides are being replaced, what else can be done at the same time to improve strength of the motor without having to pull too much more things off? (head gasket to lower compression, pistons?)

Already running pushrods and GMPP valve springs (have been told these are the same as Comp 918's)