My truck sometimes puffs white smoke when it first starts up. The tail pipe is clean of any soot. It is using a little oil but not much. I am getting bubbles at my radiator fill cap even when the engine is cold. The truck runs great and does not heat up even with the air conditioning on in this 100 degree plus weather. I do loose a little coolant somewhere. What is my problem? Blown head gasket? How much could I expect to pay if I have a shop overhaul the top end? How long can I drive it this way before I have to take action?

 

gilatrader ---

It sure "sounds" like you have a crack or leaking gasket....
When the exhaust pipe is cold, can you cram a finger into it and pull out white residue? The best way to tell is get a $35 coolant compression guage and pump the system to about 15 pounds. Crank the engine and see if the pressure **increases**...that would be a true indication the bubbles you see are combustion gases entering the coolant. Then take the heads off and look for the passage of water on the gasket....

Hoping this helps

 

Gil,
You are not describing a blown head gasket.
You are describing an old ford truck! If your truck does not over heat then you do not have a blown gasket. Do you have any coolant in your oil? That's always a biggie for me.
If the truck just puffs smoke on start up, that's your valve seals. No need to pull the top end yet, just replace the vale seals. Yeah, it's a pain but, much cheaper than going through the old bugger.
If it's a driver, then drive it. I know it's a ford, so drive it forever.
KingFisher

 

...I would guess that if you see bubbles in the radiator (make sure it's not just turbulence) then you are leaking some cylinder pressure into the water passages. If's it's not much and stops after warm up it might just be a little head gasket leakage, not unusuall on high miles but not a "good" thing either. The good part is it doesn't get hot.

In other words not a good sign but on a "driver" just keep going till it gets worse. Plan ahead!

 

[updated:LAST EDITED ON 20-Aug-02 AT 11:37 PM (EST)]It will eventually get worse, and I wouldn't suggest just redoing the top end if the engine has alot of miles on it. If you seal the topend up good, then the bottom end will like go soon due to the increased cylinder pressure. You should not have any bubbles moving when the engine is cold unless you don't have a thermostat in it or yours is stuck open. I agree that you probably have a leaking head gasket.

White smoke is water/coolant
Blue smoke is oil
Black smoke is from too much fuel (rich)

 

 

There are actual testers to diagnose this situation. I got mine from snap on but have seen the same one in a mr gasket box. Anyways heres how it works there are 3 chambers you put this blue chemical in the bottom 2 it has a squeeze bulb on the end. What you do is on a running engine you put on top of the radiator fill and pump the squeeze bulb. It sucks the vapors from rad through these chambers. If you have a bad head gasket and or cracked head there will be hydrocarbons in the vapor and the blue fluid will turn yellow if not it stays blue. It really is a great tool. If anyone gets one of these its very important that the coolant level is down enough in the rad that you dont suck coolant in it changges it to green lol and ruins it and the fluid is pricey. If you use one and it turns yellow you can clear the fluid back buy pumping the bulb in fresh air and leave it there till the next time. If you dont want to buy 1 I would think a reputable shop in your area should have 1 and be able to test your truck for a small fee.

Good Luck Andy

 

Every car or truck I owned has done this It is not a blown Head.What it is, is somthing called Condinsation which happens in the summer just as well as winter.After your truck sets all night it collects moister in the exuast from the morning dew.When you start it up your exaust heats up and burns it off causing stem to come out your tail pipe.It is posible to have a hair line crack in a head or a head gasket and cause this but highly unlikely and would get worse very quick in the summer.So if it has been doing this for a while its not a head gasket.

 

IT'S CONFESSION TIME-- I have two trucks. One is a 90 Chevy and one is a 78 Ford. The trouble I "thought" I was experienceing was with the 90 Chevy. Because this is the best forum on the net (bar none), I brought my problem to you guys. Sorry for the deception! The bubbles in the radiator turned out to be caused by a heater return hose, which returns water to the radiator just under the radiator cap opening. I do not know why it is returning water with the heater control off but I don't understand a lot of things. I just panicked when I saw the bubbles and thought the worst (blown head gasket). Well all is well, and maybe someone learned something from all this!

 

Small block Chebbys had a bad problem with valve seals going bad, causing them to smoke when started. Ford uses an umbrella type seal that hangs down over the valvestem boss. Chebby uses more of a washer type and they don't last very long. A friend of mine had them replaced 3 times under the 60,000 mile warranty on his 87 SS Monte Carlo. Bad design!!!!!!!!!!!!