Blowing out antifreeze

[95talonracer]

I have a built 2.0 and am running around 28 psi on e-85. When I hit boost I have noticed that it blows the antifreeze out the overflow. It is not overheating and there is no antifreeze in the oil. It is not burning any antifreeze either. I have arp headstuds and a Commetic metal head gasket all torqued down. Is the coolant cap pressure not high enough or what would be causing this?

[123abc]

I would try a different cap and see if that makes a difference.

[niterydr]

Sounds like a blown headgasket possible. You are pressurizing the coolant system, most likely.

[JET]

Sounds like a blown HG. Was the block decked?

[95talonracer]

Sounds like a blown HG. Was the block decked?

No it is not. When I brought it in to dyno it early in the year they overheated it on the dyno and it was boiling antifreeze out. Could that reck the gasket and nothing else. This probleb has just started in the last 2 months. Runs perfect besides under full boost. Can I just get (MLS commetic or mitsu, which is better) gasket and put it on with no problems hoping that it was the gasket or is the head warped maybe? I really dont want to have to take the motor out again. What would you do?

[JET]

If it overheated it could have definitely warped the head. I had that happen to a car, then shortly after that a rod bearing went. Mine was more drastic than yours though. I would put a stock headgasket on and see what happens, they have more give in them. You are supposed to have a decked block when going to a MLS gasket.

[Shane@DBPerformance]

Yea, sounds like a somewhat blown headgasket. You can have a barely blown headgasket that only shows itself under boost. I usually doesn't hurt power either, but can cause overheating and eventually fail in a much worse way.

Overheating can warped a head and blow a headgasket, but who knows which came first. Often overheating is caused by a blown headgasket. You might be able to just get the head decked and put in a stock headgasket. It is obviously easier to get the head decked than to pull the block and disassemble it to get it decked.

I had a problem with the 6-bolt motor that I got for my wife's 1G a few years ago. It could run or idle forever and never overheat, but as soon as you tried to do a boosted pull, it will push coolant like crazy. After trying everything and headgaskets, we had to pull the motor and get it decked. It hasn't had any problems with pushing any coolant since then.

[sleepydsm]

Lets pull the head! And then make your engine bay pretty at the same time, especially that sexy red intake manifold.

[blageo23]

Would that show up in a leakdown test?

[b00stcreep21]

bad headgasket, warped block/head, or bad t-stat housing cap. the end