SirNemesis

All,

Before I start tearing into it on the weekend, somethings gone wrong with my engine, and I'm just after some possible things that it could be.

Details are its an AES 390ci stroker setup with an LS2 block, using the original CP pistons @ 4.030" bore. LS9 gaskets, L92 heads, ARP studs @ 90#.

Setup has been fine for over a year with 15-20psi. I've recently converted it back to auto, so I'm running it at 5psi while I fix up the tune and get everything sorted again.

Was driving it to work the other day and the engine started to tick. Oil pressure remained good, didn't notice any power drop, but at the next set of traffic lights it let out a HUGE amount of blue/white smoke. The engine hadn't seen over 3000rpm all day, and wouldn't have even seen boost (I drive like a grandma most of the time). Took off from the lights again, all good, still ticking. Next set of lights, all clear, but the set of lights after that, huge cloud of smoke again.

There appears to be more breathing from the crankcase than usual, but it might just be the warmer weather (summer here).

I'm hoping it isn't something really expensive, I can't afford to throw anymore money at this car at the moment, even though I'm sure it is going to be something pretty bad...

Ideas?

80gus

sorry to hear bud. interested to know what went wrong. hope its a cheap fix for ya.

denmah

iTrader: (2)

smoking out the breather usually means a broken piston for me 9 times out of 10

SirNemesis

Yeah, thats what I was thinking too, trying to hope that isn't the case though. I mean, it isn't a weak piston (2618 forged CP, 1.2" compression height), it wasn't running much boost (5psi), bugger all timing (10 degrees) and I wasn't driving it hard at all.

I hope it isn't a piston, will cost me thousands if it is...

Bob@BruteSpeed

iTrader: (16)

Ticking and smoking out of the breather is never good! Bob

Fraser588

Without compression gauge numbers just wasting time. At least pulling and reading the plugs would've been a good step 1.

A Friend of mind did have similar incident when his rings weren't aligned properly, top and 2nd ring gaps were perfectly in line during a rebuild.

Also, what about a bad turbo?

Johnv

do a leakdown test, doesn't sound good though.
didn't think 30 thou over was recomended on an alloy LS2..

denmah

iTrader: (2)

i vote for keep flooring it till the smoke is too thick to drive

ZL1Killa

iTrader: (17)

you have worn out rings & possibly broken/damaged piston. you are getting large amounts of blowby through to the crankcase.

i have been through this. you certain the tune was spot on and safe? did it ever run lean or leaner than normal?
another question is, did it ever overboost your MAP sensor or "tune" if you know what I mean and run lean?

itsslow98

iTrader: (18)

Im having the same issue with my cobra. I was praying it wouldnt be the bottom end but i think its wishful thinking. On crutches from knee surgery so I cant tear into it. My motor has 6k miles and diamond pistons so I never expected it either. Good luck but im guessing ringland.

helga203

SirNemesis

Thanks for all the help guys. I'll hack into it on the weekend and let you know what I find...

It isn't, but the block had some decent damage due to previous piston failure and it was either that or replace the block. I haven't had any issues with the 30thou over until now, and it might not be the 30thou over thats caused the issue.

Would love to, and if I was in a different place I would, but the EPA is really **** around here. If my car makes smoke, not only will it be off the road for good but I'll probably cop a decent fine too.

dirty_old_chevy

Shove one of those snake camera things down the spark plug holes. When this happened to me, there was a hole in #3 the size of my thumb and the rest of the piston looked burned. We think my set of "flowmatched" injectors were not flowmatched very well and the number 3 one was a bit lean.

denmah

iTrader: (2)

lol sorry dude, i got a 82 fairmont if mine is smoking like a chimney and i get pulled over i say listen officer this thing is a pile of ****

owentm3

iTrader: (2)

Slap a pest control sticker on it and call it day...

9sectruck

iTrader: (9)

lol these two are funny, sorry for op

denmah

iTrader: (2)

pest control LOL

Alex in Houston

Freakin Hilarious!!!

I8UR4RD

iTrader: (16)

sorry to hear it man. looking forward to come carnage photos.

Fraser588

Warranty reman LS2 engines from GM come 4.020"

There is part numbers for oversize LS2 pistons/rings from GM