Hey guys, last night after an hour of driving my 05 Evo I had a huge coolant leak. I was WOT and all of a sudden i hear a big "BAAAAAM" noise and then smoke and coolant spraying everywhere. I thought maybe i blew a hose or a gasket

Right away i turn off the car and hit the brakes, i popped open the hood and of course just a bunch of steam coming out. I tow the car home and look at it this morning. Before even doing a coolant pressure test I did a visual, I can see something is missing.

It looks like a plug blew out...

This is right under the exhaust manifold..it looks like its from cylinder#3





any idea what i can do, can i buy another plug?

 

yes you can buy another one. they just tap in. or you can get an expandable one from the auto parts store. i dont reccomend that but it could be a short term fix. they can be hard to tap in sometimes.

 

is that called a freeze plug? what had happened, to much pressure? what is a more permanent fix?
This really suxs, I just got the car up and running good also.

 

that is a freeze plug. is your radiator cap sticking? or thermostat bad?

 

my CAP did feel a little sticky when I was going to open it, i don't think my thermostat went bad cause my temp gauge was perfectly normal.

Where can i get a freeze plug from? and do i just tap it in? cause it must of came out with a **** load of pressure.

Let me know if im on the right path of thinking why it happened, 1. I went too lean for couple of seconds or 2. too much boost(im at 27psi, evo9turbo, on e85 fully supported).

I did not think this would effect me soo much, I couldn't sleep ALL-NIGHT! Woke up right when the sun was out..lol

 

Looks like you need to keep looking . The blown out plug is a symtom of another problem ie--why and how did your cooling system get pressurized under boost? Likely a head gasket problem.

 

Definitely a freeze plug. You can get them at almost any auto parts store. You do not want to just throw in another one without researching the issue though. If you blew one out then you have a pretty good pressure issue somewhere in your coolant system.
Like stated above I would check your thermostat and your radiator cap. One of them is most likely not working correctly. If they are both fine then I would focus on your head gasket. Did you recently replace it?

 

Ok maybe im blind or just a horrible picture. But freeze plug looks like its still in there. I dont know what you all are talking about. Unless the inside of your block is painted black.

I have blown out 2 freeze plugs and replaced them. Maybe eyes are deceiving me but freeze plugs to me are all there.

 

thats the inside of the block you see... blown headgasket = high pressure= freeze plug pops out?

 

Does not look like inside of block. Stick Finger in there and prove it. I swear it looks like plug is still there or my eyes Fail.

 

I was thinking the same damn thing It looks like something is still in there.

 

your eyes are definitely failing lol In the picture you can see the other three plugs for the other cylinders are still there.

How do I install the freeze plug, do i just "tap" it in?

I am definitely going to start by changing my cap which was fizzing when i first opened up my hood right after it happened.

I don't think it is my head gasket because I checked my oil and the oil did not smell like coolant or feel like coolant and the level did not increase.

Just for my ease of mind, if my head gasket is gone (which I have never changed) will a coolant pressure test show the head gasket leak?

 

Just buy another freeze plug, clean the mounting surface a bit to ensure a better seal, get some sealant (any kind works fine really), and press the new one into place. Prob going to be a tight fit so don't worry if you have to really put some weight into it.

 

No. The head gasket can blow in different places. It may be sealing coolant away from oil passages just fine but under boost pressure the gasket is not keeping cylinder pressure out of a coolant passage and that is why your freeze plug shot out of the block - which not an easy thing to accomplish by the way.

I would do a boost leak test first to see if you hear massive amount of pressure escaping the system. Open your radiator cap and see if once the system is pressurized you have air coolant forcing its way out or air escaping via bubbles through the coolant.

You could also follow that up with a compression test to see if cylinder three is down on compression to the others since that is where your freeze plug blew from. This would be further blown head gasket evidence if it was.

 

(I would do a boost leak test first to see if you hear massive amount of pressure escaping the system. Open your radiator cap and see if once the system is pressurized you have air coolant forcing its way out or air escaping via bubbles through the coolant. )



Im sure you mean coolant pressure test. I am going to do that right away! I hope that my gasket is not blown! I guess ill find out this weekend.

Is it better to get a freeze plug from the dealer?