White smoke on startup

firecadet613 · October 23, 2003

Vehice in sig. has about 6000 miles on a new rebuilt engine I had put it. Every now and then when I start it up a little bit of white smoke comes out of the exhaust, really noticeable if it just sat for an hour, can't really tell when I start it up first thing in the morning. Running Mobil 1 right now.

Joe

robsawatsky · October 23, 2003

White smoke can be a sign of coolant getting into one or more cylinders; either through the head gasket or intake manifold.

Check to see if you're getting any bubbles into the rad, coolant in the oil, coolant level dropping unexplicably. Try to get a whiff of the smoke on startup to see if smells like antifreeze or oily.

firecadet613 · October 24, 2003

Checking coolant level in the morning. only lasts for under 5 seconds at most though. did some searching online i see it could be condensation. it was 83 and sunny in denver today?

Joe

mjsmith1223 · October 24, 2003

If it was warm days and cool nights and the truck sat overnight, then I could maybe see it being condensation. Not really sure it could form sitting for an hour or so on a warm day though.

Check all that stuff Rob mentioned. Maybe something just needs to be re-torqued.

On my truck I get a puff of bluish smoke when I start it but that's because I only start it about once a week and the valve seals are old. I get some condensation smoke/steam as the exhaust system starts to warm up, but it goes away after everything is up to temp.

Mike

Grand Haven, MI

FEAC · October 25, 2003

water in your fuel, it happens when it gets cold.

firecadet613 · October 25, 2003

Could definatly be water in my fuel. Rarely happens but when it does only lasts about 3 seconds at max.

Joe

gave20 · October 25, 2003

If your blazer is a s-10 with the 4.3 your valve seals are bad. the s10 are notorious for this. If not your valve seals good still be bad, don't quote me on this but I think to fix the seals you take the head off and shoot compressed air into the valves and it reseats them. Hopefully someone who knows more than me on the subject can add.