brink

I watched some LT1/LS1 exhaust vids, and on everyone white smoke comes out the tailpipe.. I thought that this was normaly a bad thing, and could be a symptom of a blown head gasket or if the car was just seafoamed. I started up my step dads 97Z and his 99Z, both in which have a Flowmaster exhaust system, and are stock all the rest of the way.. They both blew out white smoke at start up and a little diring rev's .. My car, 98 V6 even blows out a little smoke @ startup (i have a straight pipe +flowmaster) I know mine is because i have no cat..

Why?

fredmr39

If the smoke goes away, I wouldn't worry too much about it, especially right after start up. I know if it comes after a couple minutes and remains it could be the sign of partially blown head gaskets. White smoke at start up typically isn't serious - blue-white/gray is diffrent however...

streetheatz28

I beleve the white smoke at start-up comes from the valve seals in the heads, its really no big deal alot of cars smoke a little on startup useally happens on older or modded engines.

Lunch Box

Temperature will have an effect on it too - in colder weather the exhaust is much more visible - possibly from more junk condensing in the air, not sure

Bayer-Z28

Smoke upon startup will definety mean Valve seals...But, I though blue smoke was for oil..and white was for coolant....Smoke upon heavy throttle application, then decel from the closing throttle plate(s), usually can be traced back to a rich condition from decel. The computer corrects it, when it notices it......well, should...

Greed4Speed

You're going to have some white puffs on start up of a cold engine. Most people get clips and vids of cold start ups because this is when any exhaust sounds its meanest.

Meccadeth

I've noticed the puffs on cars when they change gears too, and coming from my car every once in a while on cold days, whats that about?

brink

well I know neither one of my step dads Z's have blown head gaskets because they both run perfectly.. The 97 with only a flowmaster catback run a 14.0 and we havent taken the 99 LS1 to the track yet.. my car ran a 15.8 tho Err... gay insurance companies, im getting an LT1 over the summer when i turn 18.