Is the head gasket toast?!?!

[steelsoldiers]

Hey y'all, I think my head gasket is going bad. Here are my symptoms: temp guage fluctuates from 190 to 230 to 200 to 250 /forums/images/graemlins/shocked.gif, then settles down for a while, then it starts going wacky again. There is cooked rusty anifreeze leaking from the front of the driver's head /forums/images/graemlins/confused.gif. Oil keeps coming up missing and it's not smoking or going on the ground. This is all happening to my cad 500 big block. No other weird things happening right now. What do y'all think?
Sincerely worried /forums/images/graemlins/angryfire.gif,
Chris /forums/images/graemlins/k5.gif

 

[GMslave]

Fill up your radiator and run it with cap off. If you see it bubbling ( like blowing bubbles under water ) it's prolly toast ( the gasket) Easy fix though.

 

[steelsoldiers]

Good tip. Thanks. I'll do that right now and let y'all know what happens.
Chris

 

[Leadfoot]

Check the oil for antifreeze and antifreeze for oil. As stated also look for bubbles. Oil could be dissappearing for other reasons as well, blowby, PCV, breather etc. As far as leaking antifreeze, check all heater/radiator hoses and connections. It could be a head gasket or cracked head (pray it's the gasket). Can be a "fun" job depending on the amount of wiring, emissions, and accesories you have in the engine bay. If you pull the heads to change the gaskets, I would have them magnafluxed at the least (to check for cracks) and depending on miles replacing the valve seals and/or going through the heads as it is the easiest it is ever going to be (heads already off).

 

[JoseK5]

The coolant should be disappearing if you got a bad gasket, Also check for coolant leaks in the hoses or at the water pump, since a lot of gasket failures are due to overheating of the head gasket, as a result in cooling system leaks. Check for water coming out of the exhaust tailpipe. You can also take the valve covers off, to check for the presence of foamy coolant and oil mix.

 

[steelsoldiers]

Well, I got no bubbles coming from the rad while running with the thermo. opened. The water is not oily and the oil is not foamy. The rad. was low on coolant by about a gallon. The mix does look rusty. The block was full of rust when I got it. I knocked the freeze plugs out and emptied as much as I could and then I flushed the whole system after the engine was in the truck. It's still rusty though. I need to pull the covers and check the front head bolts that go through the water jacket. I didn't put any sealant on them when I put the heads back on. Maybe that's where the water is coming from on the driver's head /forums/images/graemlins/confused.gif. I'll fill the rad. completely and see what happens. I need to take care of that leak though. There was some water and steam coming out of the driver's tailpipe when I first started it this afternoon. That could be my answer right there /forums/images/graemlins/ooo.gif. Thanks guys. I'll let you know.
Sincerely,
Chris /forums/images/graemlins/k5.gif

 

[Leadfoot]

One of the natural byproducts of hydrocarbon combustion is H2O so water vapor coming out the exhaust at startup (especially on cold days/nights) is completely normal. If it continues to do it when the engine has ample time to warm up, then you may have a problem. If it leaks that bad though, your coolant level "should" go down fairly quickly.