Do I need head gaskets??

[99kon]

1998 Silverado
5.7L
Noticed that when I turn the truck off my overflow tank fills up. Then I check level in radiator and I need to add water but it gets to a point where it blows the top cap off and coolant hoes everywhere.

Am I right by thinking it needs head gaskets?
Oil is nice and clean
Replaced radiator cap with new one
Truck has 190k miles
It does have a random miss p0300

 

[phule]

Could be a stuck t-stat

Adam

 

[SCOTTYINWV]

I'd try a t stat 1st

And a shop can pressure check your cooling system and cylinders...

 

[Ruger_556]

T-stat first... You could do a leak down test too

 

[JollyGreen]

Does is still have that awesome GM Dexcool in it?

 

[99kon]

Antifreeze has a green tint to it but is slowly getting replaced with water.

 

[99kon]

I have a compression tester and will check tomorrow