White smoke when thermostat opens
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From: Baltimore, MD
Car: '86 berlinetta
Engine: carbed 350
Transmission: T-5
White smoke when thermostat opens
I just put in a freshly built 350 and have only drove it a few times now. I have noticed that when it is idling after start up white smoke exits the exhaust pipes. It is significantly more noticable after the thermostat opens (the car gets up to temp). It does not smell sweet or anything like antifreeze. It just seems like exhaust. I know something is not totally right if, after it gets warm, more white smoke comes out.
I have frequently checked the plugs and they are pretty black so I definitely do not think it is because it is lean.
I am going to try a compression test next time I am home (at school now) but in the mean time I'm trying to evaluate the possibilities. Is there a particular gasket leak that could be causing something to enter the cylinders when the thermostat opens? Anyone have a similar problem? Any ideas would be great. Thanks!
I have frequently checked the plugs and they are pretty black so I definitely do not think it is because it is lean.
I am going to try a compression test next time I am home (at school now) but in the mean time I'm trying to evaluate the possibilities. Is there a particular gasket leak that could be causing something to enter the cylinders when the thermostat opens? Anyone have a similar problem? Any ideas would be great. Thanks!
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It's steam.
Completely normal.
The single biggest chemical component of exhaust gases, is WATER. All of the hydrogen in the fuel turns to water when it burns. When the exhaust ssystem is completely cold (for the first minute or so of running in the mornign), all that water condenses before it makes it to the tailpipe, so the exhaust runs clear. Then for the next few minutes, all of that liquid water evaporates as the system gets hot, and appears as steam. That's what you're seeing. Then after a while, the exhaust coming out is hot enough that none of the water condenses, and it's clear.
It has nothing whatsoever to do with the thermostat, as such.
Completely normal.
The single biggest chemical component of exhaust gases, is WATER. All of the hydrogen in the fuel turns to water when it burns. When the exhaust ssystem is completely cold (for the first minute or so of running in the mornign), all that water condenses before it makes it to the tailpipe, so the exhaust runs clear. Then for the next few minutes, all of that liquid water evaporates as the system gets hot, and appears as steam. That's what you're seeing. Then after a while, the exhaust coming out is hot enough that none of the water condenses, and it's clear.
It has nothing whatsoever to do with the thermostat, as such.
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Junior Member
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From: Baltimore, MD
Car: '86 berlinetta
Engine: carbed 350
Transmission: T-5
I ruled that out because of how clear it was when it was cold. I thought the steam would be coming out if it was cold, but it comes out so much right when it warms up. What you're saying makes complete sense, though.
It just happens for a long time when it's warm. Like twenty minutes or so after i've gotten past about 180 degrees. I guess it just condensed a whole lot. Thanks.
It just happens for a long time when it's warm. Like twenty minutes or so after i've gotten past about 180 degrees. I guess it just condensed a whole lot. Thanks.
Thread Starter
Junior Member
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Joined: Jul 2003
Posts: 26
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From: Baltimore, MD
Car: '86 berlinetta
Engine: carbed 350
Transmission: T-5
It stays the same. I'm just being overly cautious seeing as how this is my first build. I just need to drive it more.
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