My Iroc is catching smoke

I need some help with this. If the cars been sitting for awhile the coolant tank will show its completely empty, but after 20 mintures of driving it there will literally be smoke coming out through the hood. The smoke comes from the coolant tank reservoir. The coolant will bubble up all the way to the top as if I was boiling water over a pan. Today I saw the same thing, but coolant was also spraying out of the radiator cap real violently. There's coolant all over the engine bay. This might be worth mentioning, I had a mechanic just recently put in a new 5.7 engine into the Iroc in question. Any suggestions?

possible head gasket? Maybe due a cyl leak down test or cooloant system pressure check.

Matt

It sounds to me like there is a hole/crack somewhere in the block that let's the combustion relieve itself into your coolant system instead of just when the exhaust vavles open. Or it could be a crack/hole in your heads doing that too...Or maybe a head gasket leak...hopefully just a head gasket leak.

Good luck!

Take out the thermostat and see if it still does it. If you had a crack in the block or something like that then steem would be comeing from there. If it was a blown head gasket the you may the water in the oil witch will look kinda white, or you will be blowing white smoke (steem) from the tailpipe.

The engine before this one had a blown head gasket and a cracked engine core. This new engine is sharing all the parts from the old engine. I forgot to mention that it's consuming a crazy amount of gas. I went from 3/4 tank to 1/8 tank in 20 miles.I just want to know why is my coolant boiling hot and what's with the gas mileage?

Well the gas thing maybe be just a bad gauge, a common problem in the 3rd gen camaros. Did you use the old water pump? If so that may caused the problems with the old block and will cause it with this one.

I think it was a loose radiator cap the whole time. I'm still not sure, but the smoke hasn't occured yet since. Maybe I'm really low on coolant or something since most of it leaked out, but I'll check it out tomorrow.

Loose radiator cap causing that much smoking really? Unless it was splashing on to the hot engine block and burning Im a little confused.

Having a loose cap is like having a bad one. It will cause the car to over heat.