Rough Engine Idle, White Exhaust Smoke

Hi everyone--

Heres the deal: driving to LA last week, had to fill up at a crappy gas station, and the whole drive down my 63 390 was not having its usual power and it actually stalled in traffic because the idle got down so low. Started back up easily after I punched the gas. Anyway, now when I start her up there is a TON of white smoke that comes out of the exhaust. From what I can tell it goes away after driving for a while.

I just tuned her up last week (timing, carb adjustment...) although it might be time for new air filter and distributer cap and rotor (the engine is stock except for pertronix coil and Ignitor). Could this be the problem? I hate to see her running this bad.

Thanks! Geoff

PS--I have been gone for a while, life got in the way of the car hobby--but I am making a comeback this winter! I look forward to reading about all of the cars that were projects a year ago!

Take a quick readding on compression pressure. You may have blown a gasket or have intermittant leaks. Pressure ought to be greater than 120PSI for the sea level area you are in.

Wm.

White smoke means water..... Head gasket maybe gone.

Check your oil stick, does it have white foam or white sludge on it?

Run it for more than 15 minutes as long as the temperature stay's in the safe range.

If it's only built up condensation it will burn off but may take a while.

Keep an eye on the temperature.


FE
P.S. Run it for a moment with the rough idle then check all the plugs for a wet one if you don't want to run it long enough to cook off all the residue...
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I would think that considering the reported vicinity in address, there isn't much of a chance there would be even an ounce of condensation within exhaust system.

Basic thought is that there is a combustion leak. Can be first found by a compression check, or maybe a radiator snifter.

Wm.

Thanks guys,

I am going to do the compression test today, I will let you know what happens

Geoff

Coosbay... Santa Barbara has LOTS of morning Humidity... At least it did have everyt time I was there, and especially nearing winter time... Anyhow...

A compression check is a good thing, it sound's like your head gasket is bad but it seems to be a slow leak that pours some coolant into the exhaust after shut down, because you said it threw white smoke for a while then burns off... A compression check might not see that blown head gasket as well as one might think...

Keep us informed!

FE
[addsig]

If you filled up at a crappy gas station, you may have a good deal of water in the gas. This happened to my dad's '82 Jeep. It had the same symptoms, and it was right after he filled up. Did a comp. check, every cylinder was good, we pulled the top of the carb., and it was mostly water. You may want to do a compression check first, if nothing shows up as being bad, you may want to look into it being water it the gas.
If it is water, you need to drain the gas, at least your engine will be steam cleaned in the chambers(kidding).
Good luck, Chris.
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Update:

So I couldnt run the compression test as planned (my buddy couldnt find the tool), so it will be delayed until next week or so. However I did fiddle with the engine last night, heres what I found:

-No smoke at start up, then after warming up 5 min a little came out. I revved it a few times and some smoke came out, its a whitish grey color. Then then smoke seemed to die down.

-No white sludge on oil stick--it is clean as a whistle.

-More black soot than normal noted on the ground beneath the exhaust pipes and the exhaust seemed to smell more like gas than normal. Could this be part of the problem?

I cleaned the carb and checked timing to finish things off and everything looked okay. Any suggestions until the compression test? Thanks for all of your help!

Geoff

A bad modulator valve on the trans will cause white smoke and could cause a rough idle. Jeff
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