Smoke on Startup

[valkyrie]

Before I get yelled at I have searched for the threads relating to this. I am just looking for something more diffinative and current.

When I had the car in for mods Mike noticed a white cloud of smoke only on startups. After starting up it goes away. A lot of other threads mentioned blue but I see mine as white.

At one of our gatherings Nexstar thought he smelled fueled when I started up and told me that I appear to be running rich. Can this be attributed to the white smoke on startup?

[merc406]

Yes...............

[DEFYANT]

I thought white smoke was really steam, blue is oil and black is excess fuel?

[merc406]

Had a stuck float on one of the carbs on the 63 when I bought her. Car ran but emitted white smoke. Pulled the plugs to find that the last carbs banks it feed were pushing gas. Only other time I've had that kind of white smoke before was when carbon cleaning with trans oil.

[RF Overlord]

I always thought that blue=burning oil, black=way too rich, and white=burning transmission fluid or coolant. Since the 4R70W doesn't have a vacuum modulator, there's no way to get ATF into the combustion chamber, so I guess that one's out...I hope it's not coolant, either...

Can you get it on a dyno and have the A/F checked? It may be that simple...

Wasn't your car running rich at Indy?

[Krytin]

I did notice a lot of what appeared to be water running out of your tailpipes at the last meet we were at - I figured it was excess condensation from the repeated starts in the parking lot while you were demonstrating the kooks exhaust ala remote starter! The new exhaust might be cooling/condensing the water vapour during start up. See it you get the puff - or as large a puff w/hot pipes. After an extended run on the highway, as soon as you can pull over & stop, shut the engine off & get around back w/the remote starter and see what happens on a hot start.
If you're not loosing antifreeze - have the A/F ratio checked/retuned (if needed) and drive on!

[TripleTransAm]

When I came home to a significant snowfall Saturday night, I went back out after dinner to clean off and move the Marauder. Always one to enjoy listening to the Marauder purr on startup, I used the remote starter. Now this situation was ideal for watching exhaust smoke... pitch dark all around, the floods on the house turning the snow around the Marauder into a white reflective blanket... perfect for detecting the color of smoke emitted from a tailpipe.

The verdict: a *definite* puff from each tailpipe at startup. Color: black. Woohoo. had this been in 2003 I'd have been expecting blueish-white. No doubt about it, the MM fires up rich, some programs richer than others. Great part about CRD1 is that I can hop in it right away after startup, and it runs within 95% of how it runs when at operating temps. :up:

[Motorhead350]

Mine has omitted blue smoke on start up for one year and nothing seems to be wrong with it. Even after an oil change.

[David Morton]

This water vapor is normal. Defyant is right, Blue=oil; Black=fuel; I would add White=water or coolant. Because it goes away after warm up, we can eliminate coolant.

While I'm here I'd like to explain what's going on here. The internal combustion engine produces a lot of water vapor as part of its combustion by-products. Catalytic convertors add even more vapor by further burning. On start up, there's not enough heat to boil off this vapor into steam which is invisible so that's why you're seeing the white water vapor. Steam is condensing into water vapor very soon after it leaves the exhaust pipe on very cold days, so this effect may be more pronounced in the cooler weather. Once it warms up, the steam becomes superheated and has time to get much further away from the pipe before it condenses into visible vapor but is so dispersed by that time, you don't see it. Unless it's very cold day.

Try holding your hand in the exhaust for a while, it'll get wet. Though it doesn't smell like anything you'd want to drink, that is water that is wetting your hand.

[Krytin]

This water vapor is normal. Defyant is right, Blue=oil; Black=fuel; I would add White=water or coolant. Because it goes away after warm up, we can eliminate coolant.

While I'm here I'd like to explain what's going on here. The internal combustion engine produces a lot of water vapor as part of its combustion by-products. Catalytic convertors add even more vapor by further burning. On start up, there's not enough heat to boil off this vapor into steam which is invisible so that's why you're seeing the white water vapor. Steam is condensing into water vapor very soon after it leaves the exhaust pipe on very cold days, so this effect may be more pronounced in the cooler weather. Once it warms up, the steam becomes superheated and has time to get much further away from the pipe before it condenses into visible vapor but is so dispersed by that time, you don't see it. Unless it's very cold day.

Try holding your hand in the exhaust for a while, it'll get wet. Though it doesn't smell like anything you'd want to drink, that is water that is wetting your hand.

Yep, all that and watch the pH on that wet stuff - it can & will cause some chemical burns if left on your skin long enough!