Denial

[ColdBird]

Well, i changed the t-stat in my car (which was bad) but i started it and it made a suspiciously larger than normal cloud of steam. I let it idle and it stayed cool, but you could smell hot antifreeze from my neighbor's house. I cant think of anything less than a blown head gasket. Any ideas on cost to have a shop do it? I froze my butt off just doing the thermostat

[raroZ28]

A shop you are looking in the thousands. Doing it yourself you're looking at 100 in gaskets. Your call.

Did you check the oil for a milky color? I would say check the compression but it's so damn hard on these cars, I can understand not wanting to. I'm just saying don't replace what isn't broken, until you know for sure.

If the oil is clean it might not be the cylinder head. A good compression check will make it positive.

[Kevin - Blown 95 TA]

You need to see where it's leaking from first. It might be coming from the t-stat housing. I had mine leak from there for some reason one time. When mine leaked after I changed the stat, I turned the gasket over and cleaned everything then put it back together and didn't overtighten - worked. Those stock screws are also soft and can break if torqued to the spec in the book. Now I didn't really understand if you had an overheating problem or no heat from the heater or just why you changed it in the first place. Don't forget to go through the ritual of bleeding it a couple times to get the steam out of the heads or it might spit some hot coolant out the overflow. You need to bleed and refil at least a couple times to get it right.

[Injuneer]

Did you get the correct t'stat for your LT1? Reverse cooled system requires a special 'stat.... most auto parts store will sell you the one for a Gen 1 Chevy, because they don't know the LT1 takes a special 'stat.

Hopefully, you are using the "how to's" on Shoebox's Tech Page

Shoebox's Tech Pages

[ColdBird]

This is AFTER i changed the thermostat, and yes i did use the right t-stat. It is leaking into my cylinder so it must be a head/block deformity/crack or a gasket, correct?

[raroZ28]

If you have coolant leaking into your cylinders, you had better pull the heads off and get it cleaned up quick. Don't let your rings rust to the cylinder walls. That'll call for pulling the motor, honing it out, new rings... Big job. I have heard of a few guys that blow head gaskets, let it sit, and when they get around to doing it the motor is shot.

[ColdBird]

Ouch. No, im taking care of it tomorrow. Hopefully the head's not warped but my machinist friend says it will more than likely have to be skim cut ~ 0.010" but we'll see.

[Joe 1320]

This is AFTER i changed the thermostat, and yes i did use the right t-stat. It is leaking into my cylinder so it must be a head/block deformity/crack or a gasket, correct?

Typically, the metal fire ring degrades and seperates from the composite gasket. The fire ring is what is responsible for sealing the cylinder. if you didn't let the car seriously overheat, you probably did not warp or crack the head.

[raroZ28]

Ouch. No, im taking care of it tomorrow. Hopefully the head's not warped but my machinist friend says it will more than likely have to be skim cut ~ 0.010" but we'll see.

I doubt the head is warped or cracked. However, it is usually a rule of thumb to have your aluminum head milled a little once it's pulled. Doesn't take much to warp those alum. heads. You could probably get away with not milling them, but you still have to take them to the machine shop to have 'em checked.

[beachbum86]

Ouch. No, im taking care of it tomorrow. Hopefully the head's not warped but my machinist friend says it will more than likely have to be skim cut ~ 0.010" but we'll see.

While the heads are off... Port and polish maybe??? Just a suggestion. Kill two birds with one stone type of thing

[Joe 1320]

One thing that helps is to remove the head fasteners in the exact reverse order as assembly. This prevents alot of warping. BTW, a simple straight edge will determine if the head is warped.

[raroZ28]

straight edge'll do the trick. I would just let a shop do it though. They'll pressure check it for cracks, and check for flatness. Should be free, and if it needs milling I think it's about 40 bucks.