antifreeze shootout of the filler neck

[un4givin68]

OK so i just did the head on the car. It ran great for about two days and the radiator blew out. I literally mean it blew out i thought it was the squirrel that i hit that took it out. So i put in a new radiator today go to fire it up and it blows all of the antifreeze out of the filler neck. Not just bubbling over but it is a two foot geyser out of my hood. Any suggestions on how to fix it would be greatly appreciated or some were to start. I appreciate all the help in advance.
Richard

 

[Splitpi]

Something is causing tremendous pressure build up in your coolant system. Most likely an over heating and/or the cylinder's leaking pressure into the coolant causing the system to build up pressure and once it warms it increases that pressure till you have a geyser. My first instinct is to think it is something to do with the HG.

 

[un4givin68]

OK i will check it out. But it is not doing it when it is warm i didn't even let it get warm. It did it as soon as i turned the key sorry i forgot to add that.

 

[Splitpi]

OK i will check it out. But it is not doing it when it is warm i didn't even let it get warm. It did it as soon as i turned the key sorry i forgot to add that.

I am still thinking you are pressurizing the system via a leaky HG into coolant system. You figure the cylinders are beating ~400 rpm at startup generation ~170 psi that would pressurize the coolant pretty quickly just trying to kick the engine over. But this is just my gut feeling... and it could be something else. Go over in your head your HG installation and make sure you did everything correctly.

 

[un4givin68]

OK i will pull it and get a new mitsu hg. Cause like i said i drove it from Friday till Sunday afternoon when it blew out the radiator. Thats what my grandpa said as well but he doesn't know these cars like most of the ppl on here thank you for the advice. I will give it a shot and try it again.

 

[cooldude919]

I will agree with what has been said. It was fine before probably because the HG was fine. The HG ###### blew right before your rad did. As was said, exhaust gasses probably leaking into the coolant system (sounds like a lot from your case) and apparently the rad was the weakest link, so it blew. You sure you torqued everything to do with the head down correctly? Something must have been off for it to blow like that so quickly.

 

[un4givin68]

Yea my grandpa owns a shop and does the head and timing belts all the time. The hillbilly's around here just wait till it breaks and then fix it . i was talking to ABEL Racing and they said that the gasket could have been bent a little which will cause it. They had one come back doing something similar to mine because the head gasket they had put on had been bent and they didn't know. It so i will order a new head gasket and try again. Thanks again
Richard

 

[Talesin]

I had this same thing happen to me, once. It was an improperly installed MHI metal HG... when going with a metal HG, both the head and the block need to be decked almost mirror smooth before the HG is applied, or it's very unlikely to seal correctly. Crank the engine and had coolant rush the overflow reservoir. Tried it again with the fill neck cap off, and coolant went everywhere in a geyser that hit the underside of the (opened) hood. Should be able to start your car with the fill neck cap on and run it for half a minute or longer before it starts to overflow from heat expansion.

Something that dramatic sounds like the same problem.. pressure from a cylinder's compression stroke getting shunted into the coolant system.

 

[un4givin68]

at least i now know i am not the only one that has had this problem. This sucks but hey what can you do i want my car running again. It drove and ran great for 2 days i have not been able to drive it since October.

 

[Splitpi]

I agree with talespin says about decking the head and block if you are going with a metal HG. Just get a cheapy Mitsu stocker instead... people have been putting down very decent HP on the stocker's with out failure. It may save you some money and give a better seal.