White Smoke From IACV

[Davo53209@yahoo.com]

Just moments ago, I pulled my car into the garage so that I could set the ignition timing on my 94 Civic VX. As I ran the engine with the hood up, I'd noticed a stream of white smoke was coming off of the idle air control valve.

My first thought was that a hose melting; but that apparently was not the case.
The other thing that I'd noticed was that my coolant reservoir tank has gone from full to half in about a week.


What I should also mention, was that about two weeks ago, I had taken IACV off of the engine and cleaned it out thoroughly with carburetor cleaner. Up until now, I didn't appear to have any problems. Are any thoughts of what the problem could be?

[Superfuelgero]

The throttle body is heated by coolant. I'd pull it off and check for cracks/leaks. You can also just bypass it.

[Davo53209@yahoo.com]

You know I just realized something. Isn't one of the screws longer than the other? If so, I'm starting to think that I may have switched them up. Does that sound like a probable cause to the white smoke?

[Davo53209@yahoo.com]

This morning I checked the IACV, while noting that it didn't have any cracks on it. I did attempt to remove the bolts; but they were on to tightly. For I decided that it was best to keep to keep it on, instead of breaking a bolt.

[some_other_dave]

See if you can sniff the smoke. Just a bit, in case it's toxic! Does it smell sweet? In that case, it's coolant. Look for anything with coolant lines running to it in the general vicinity. Like the throttle body that was already mentioned. The hoses can crack with age, or with being moved around or bumped. There may be other bits that have coolant plumbed to them; look at all of them and all of the coolant lines.

-soD

[Davo53209@yahoo.com]

You know, I had considered that it might be steam, and you may be right in replacing the hoses. I haven't started the car today; but I plan on taking it out the freeway soon for a test drive.

[Superfuelgero]

Lots of lines to check.

[Davo53209@yahoo.com]

Originally Posted by xntrx

Lots of lines to check.

Incidently, I'm going to need this for when I flush and fill my cooling system, so thank you in advance. As for now, I just did a 20 mile test drive on the freeway before looking under the hood and ironically, there doesn't seem to be a problem; but I'm not yet convinced.

Given what we know goes through the IACV, I'm thinking that it was probably steam. This in spite of the fact that the apparent smoke was billowing up like something you'd see coming off of the end of a cigarette.


The only thing that I've done differently was to fill the resevoir tank back up to full so for now, I'm just going to keep an eye on the situation.