Visible exhaust when cold?

[SLC97SR5]

Why do some vehicles continue to emit visible exhaust "fog" even after they are warmed up?

My new to me '87 4Runner "fogs" continuously during cool weather. It has a fresh tune-up, passed emmisions flawlessly, and has been run long and hot enough to expel any exhaust moisture.

I always assumed that other peoples rides we ill maintained, running rich, bad cats or simply not warmed up.

Of my 5 Toyota's this is the first to exhibit this condition.

What say RME?

 

[lewis]

Crack in the head and coolant seeping out, time for a tacoma! I remember in thermodynamics it has something to do with the wet bulb temp and humidity and other factors while its warming up. Why it only happens on that rig all the time is a wierd.

 

[SLC97SR5]

Oh man, wouldn't that be neat...I could go for that but there is no coolant loss, nor oil/water mixing. The "fog" is not apparent during warmer weather, nor is it white like a blown HG.

 

[lewis]

Did you smell it? Also where do you buy gas for it. I had a similar prob with my 88 truck when I bought maverik gas.

 

[bryson]

Mine did it all the time when the head gasket was bad... Once it warms up, there is no reason for the fog if things are running right.

 

[OREGON85]

That what mine did when the head gasket went out.

 

[lewis]

So is your truck not warming up? The block may not be getting warm enough?

 

[SLC97SR5]

It does not smell like coolant, but it does smell slightly rich...definetly a fuel smell not an anti-freeze sweetish/metallic smell.

Would an out of adjustment TPS contribute to this?

I bought it's first full tank at Costco although I used 85, not the recommended 87 per the manual. However 85 is usually what I put in all the Toyota's.

 

[SLC97SR5]

So is your truck not warming up? The block may not be getting warm enough?

I think so. The PO said it had a 190* T-stat and the gauge comes up quickly to normal. I have yet to put a temp gun on things to verify. The fan clutch is operable and the heater blows pretty hot, not as hot as others so I may have a t-stat issue.

Perhaps totally unrelated but I don't have a cold idle (waiting for ricsrx to chime in on this one).

 

[ricsrx]

Ya John i got a lead on that from piriat but because the 22re ran so well and warmed up quikly i never followed up on it, let me know if you want to tackle it...

 

[SLC97SR5]

Ya John i got a lead on that from piriat but because the 22re ran so well and warmed up quikly i never followed up on it, let me know if you want to tackle it...

Let's see the link

Any other ideas?

 

[jsudar]

Water vapor is a byproduct of the combustion of hydrocarbon fuels--like gasoline. When the weather is right you can see it as fog. Just like you can see your breath when it's cold. When it's warmer, you and the Toy are still exhaling water vapor, you just can't see it.

I'm not saying you don't have coolant in the exhaust, that could still be true, but it is perfectly normal for a healthy engine to make fog when the weather conditions are right. Wait till it warms up next week and see if it still does it. Put your hand by the exhaust pipe while the motor is running and you will feel the vapor whether you can see it or not.