hello guys, I just bought a 2005 GXP with 40,000 miles on it a couple months ago

one day I started it up and a bunch of white smoke came out of the tail pipes, but this has only happened once since I had it, does anyone know what this might indicate if anything at all, I just thought it was weird it only happened that one time

It happens. I have seen it myself rarely and haven't a real explanation. Possibly a sensor taking it time to catchup with the PCM program? All Northstars like to seep oil past the rings as well so? Another thought was water condensate beyond the cat? Whatever the cause, mine has done it here and there from the beginning.

thanks for the reply Venom, i feel much better now

was it cold when you started it? mine blows quite a bit of white smoke when i first start it.

My '05 GXP with 67K miles has never blown white smoke of any kind at startup.

If it regularly did this it could be oil leaking around worn valve guides into the combustion chambers. Also coolant getting into the combustion chamber could cause this.

However your symptom is probably too intermittent to be one of these. As everyone has indicated don't worry about it unless it starts happening much more frequently.

Enjoy your GXP, they are fun to drive.

Every gallon of gas you burn produces a gallon of water, normally this comes out of the exhaust as superheated steam and you don't see it.
However if you have made a few very short trips the water can condense in the exhaust and give the symptoms you describe. Quite often I can see water trickling out of the exhaust of the car in front at a stop light and can guess it has not warmed up yet.
If you haven't used any oil or water you probably have nothing to worry about.

for reply guys

nope, the temps were about 80 plus degrees that day, this has only happened once and that was about 2 or 3 weeks ago

it was the first and only time it has happened since I bought the car a couple months ago, car has been running fine otherwise

mhmm kinda weird for such low mileage, but i admit ive seen it few times on mine too

one thing I remember though about that day it happened, I did a hard acceleration earlier that morning on my way to work about 8am ( dude in his lil camaro didnt wanna let me over trying to speed up so I had to show him the Bonnie tail lights and got over on my on demand ) then after work about 5 pm when I started it up thats when all the smoke came out the exhaust

nomunk,

Were you planning on addressing this issue with the dealership? Please keep us posted.

Thank you,
Caron, GM Customer Service