Chevrolet Repair: Steam, lumina car, head gasket

Question
I there again.  I checked the resivoir, and it was full.   It had overheated twice, within the week before.  That is what puzzled me on why the resivoir was full.  When you shut the car off from the overheating, your heard bubbling of the antifreeze in the resivoir.  After you did that, it would drop back to normal temperature.
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Hi there, I have 94 Lumina car, and the other day when I was driving it, it started pouring steam out the vents, and a cloud of white exhaust behind me.  I have not drove it since.
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Hi Joe,

Did it overheat?  What is the level in the radiator; I know you cannot see that, but what is in the overflow bottle?

If this is for sure coming from exhaust, then this sounds like a head gasket.  This is without seeing the car and without more information.  The smoke in the vents could be from the outside air being smoky.  

You need to check the appropriate areas for a bad head gasket.  

1.  Level in overflow is low or empty.

2.  Oil is milky.

3.  Compression on one, or two adjoining cylinders, is
   low.  This corresponds with fouled plugs on these
   cylinders.

Could be a big job.  Good luck.

Hope this helps.

C J S

Answer
Hi again, Joe,

If you are gurgling in the reservoir and it has a level, then you may have less of a problem than first thought.  

Are you sure the smoke is coming from the exhaust?  How is the car running?  Is there power when you step on the gas?  Is the oil milky?  

White smoke is steam.  This is from over heat or head issues.  If the smoke comes from the exhaust, and the oil is fuller than usual and milky, then you have head/head gasket issues.  However, if the oil looks good, and the level is up in the coolant reservoir; then we may have only a collapsed hose or a bad thermostat.  

This is what I would do.  After looking at the oil, start the car.  When it overheats, look around for a hose that looks like it is being pinched with pliers.  If you don't see one, then suspect the thermostat.  You will change this anyway, if/when you do the head.  

White smoke in the vents is just intake from the outside air.  White smoke in the rear of the car could be just the wind blowing the steam that way.  Smoke from the tail pipe is a concern.  

Hope this helps.

C J S