is this a bad head gasket

[aric70chev]

Noticed on a cold start there will be a bit of white smoke but then clears up engine doesnt overheat but acted like it wanted to die i pulled over and popped the hood and the radiator was hissing then i touched the cap and it shot fluid out of the overflow i opened it up and saw little bubbles in the antifreeze i filled it back up since then it runs fine untill it warms up then it wants funny and likes to puke antifreeze was thinking bout trying blue devil sealant
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[Wrenchbender Ret]

Sounds like it might have a head gasket or cracked head leak. Sure sounds like it is overheating also. I would check the therm. Put a can of Bars leaks in it. They have a new one out for head & block sealing.

[storm9c1]

Man, I don't like using that sealing stuff like Bars. Last time I used it, it clogged my heater core solid, the water pump went bad, and when I took it apart, there was all of this ceramic like plaque all over the impeller. And the WP bearings were shredded. When I read up on it, that stuff is some type of silicate in high doses. The same stuff that was used to kill cars during cash-for-clunkers (albeit when added to oil). That stuff is evil. Never again. Only use it if you are getting rid of the vehicle ASAP.

If you are generally overheating due to another problem, your coolant will bubble and boil, especially if your system isn't holding pressure. However, if you are seeing bubbles when cold, you got a big problem.

Instead of snake oil, I suggest doing some diagnostics. Go to Harbor Freight (or order online) and get a radiator pressure tester. Then you can see if your rad pressure climbs way above normal when you rev the engine or pull a load.

If so, pull the heads and replace the head gasket. Do it right.

[Boogie_Man]

Time for an oil change. Look for water/coolant in your drained oil. That's a sure sign that you've got a cracked head or blown head gasket.

[butch86]

i hear of people who sware by the quick fixes. thats just a bandaid if it works at all. some of the parts stores have pressure testers in there loan a tool program.

also make sure your system is full of water and there are no air bubles in the system. if your pressure changes with reving the motor you more than likely have a blown head gasket. as stated above.

my personal opinion is never ever add those mirical block sealents or head gasket repair fluids. if you ever work on a engine after that crap you will understand it does way more harm than good.

[68gmsee]

I agree with the blown head gasket/cracked head theory. I've used leak blockers before but used them as a quick fix until I got to where I needed to go or until I could fix it properly. I personally have never seen one work on a permanent basis. Eventually one has to bite the bullet and fix it right.

A leak in the head gasket or a crack may not be noticeable with a leak pressure tester. Sometimes these act up only after the engine warms up so keep that in mind.

If it's bubbling when cold there's a leak somewhere. Also if it's forcing fluid out of the cap and losing coolant. All the symptoms are there.

[storm9c1]

Originally Posted by 68gmsee

A leak in the head gasket or a crack may not be noticeable with a leak pressure tester. Sometimes these act up only after the engine warms up so keep that in mind.

True, in this case you need to get creative. You can tee in a section of hose into one of the heater hoses or intake nipples and run it into the cab (even if it's through the window, it's just temporary). Stick a pressure gauge on the end (any good water pressure gauge will do), and drive it around, pull some loads. Make sure the hose and gauge connections are good for 50psi just in case. Done that before to diagnose these types of things...works well.

[Gumby]

^ um id duck tape it to the outside of the window, I can see someone doing that, the gague comes lose, shoots at them like a rocket and then they get sprayed with boiling hot water as they drive into head on traffic