Ok this is weird, over the weekend I noticed that my car was leaking coolant from one of my hoses so I got around to tearing it apart and there was a crack in the hose which I now have replaced. So I start the car up and there is a leak from another hose! So I checked the clamp an everything looked fine. Well I decided to grab my pressure tester and test my cooling system! With 18lbs of pressure applied to my cooling system no coolant was leaking anywhere.

So I removed my radiator cap and with the car off I flicked on my electric waterpump and watched as the coolant circulated like normal. Well then I put the radiator cap back on and started the car up. I let it run for like a min and then I notice that the hose is leaking again. So I shut the car off and as I go to uncap the radiator cap I can tell its pressurized BEYOND 18lbs! I have never seen it do this before especially on a DEAD COLD engine.

So on a hunch I left the cap off this time and then started the car and it was like Old Faithful except that coolant was spouting out of the top of my radiator! Its like there is something forcing too much pressure into my cooling system which is why when the car is running there are hoses leaking because there is TOOO MUCH pressure building up in the system for some reason..

Anyone have any ideas as to what this could be?

 

System might just have to much air trapped in uit, when you start it steam bubbles form and the ony way out of the cooling system is the radiator vcap or the leaky hose.

 

Eh I don't think it's that because when the car is off I can run my electric waterpump with the cap on and it doesn't leak one tiny bit! Nor does the pressure get near as high with the engine off. Although I was thinking the air pocket thing but I just don't see how an air pocket could make coolant spit from the radiator cap like it did

 

It is common with our set-ups to have what you describe. It probably just has air in it. You can search on bleeding the coolant system.
What I like to do it pull the car up on jack stands and start it up with the cap off and fill it up as it uses up the water and gets up to operating temperature. Don't have to risk getting any coolant dripping on the opti using the vent screw.

 

The easiest way to bleed it is with a cold engine, open both bleeder screws and fill up the coolant, and close each one off when coolant starts to come out, then top off the radiator.

 

hmmmm well I dunno I am glad you guys think it's something small but I am still skeptical! I still don't think it should be bursting from the radiator cap like it does. I mean if that were the case then how come I can run my electric waterpump with the car off and it doesnt have any problems circulating? Why does it only act up when the car is running?

 

That wouldnt make it that dramatic.

If it was air, it would do it anytime the EWP is on. Whether the engine is running or not makes no difference.

More likely, it is compression leaking through the head gasket, or head(cracked) and into your cooling system. This will cause it to "blow" antifreeze out of the radiator cap.

I hate to be the breaker of bad news, but this is more likely than air in the system.

Think about it:

What difference does it make that it is running? Your EWP runs at the same rate whether the motor is running or closed. If it doesnt do it with the EWP running, circulating the water, with the engine off ... Then if you start the engine and it blows it out, where is the extra pressure coming from? The EWP is still spinning at the same rate. Nothing actually changes in the cooling system with an EWP. Its compression leaking past the head gaskets or through the head if you have a cracked head.

Good Luck

 

Sorry that post is hard to read. Its late, Im tired.

 

Yea I knew it. Thats kinda why I kept reposting that I don't think it's somthing simple. My thoughts were the same as yours as "why would it only do it with the engine running and that the extra air has to be coming from the compression of the cyls". I just wanted someone else to verify what I was already thinking I hope to hell it's just a head gasket! If one of my AFR Heads are cracked I am going to be one PISSED OFF F-Body owner

Also I am wondering that if it is a head gasket leak then why am I not burning coolant thru the exhaust? Shouldn't it be puffing white smoke out the exhaust from coolant leaking in there?

 

BTW is there a way that I can test to make sure where the prob is coming from? Perhaps a leakdown/compression test

 

Sounds like a blown head gasket to me also.

 

Yea that's fine I just want to make FOR SURE before I go ripping my heads off. Also I wanna start researching for some better head gaskets rather than just using the felpro ones again!

thanks guys

 

Umm, no!. The EWP dont make heat in the block

You need to bleed it man. The block had air in it, and when it gets hot (engine running) the thermostat is opening and letting the air out, and its taking coolant with it. Why would you have a blown head gasket after changing a hose because of a little leak?

 

Oh yea, blown head gaskets will cause bubbles comming out, not old faithfull. If it was a blown head gasket, you'd get water in the cylinders when you pressurize it, and it would smoke when you start it up.

 

Nah dude I don't even run a thermostat in my car. I believe its a blown headgasket because a few nights before all this occured I was racing and my electric waterpump failed on me. I know this because I have my car wired to shut off if the oil pressure drops below a certain psi, OR if the water temp gets above a certain temp. In this case the water temp got past 230 due to the waterpump quitting on me. It turned out that one of the STOCK BOLTS on my CSI waterpump came loose due to vibration as seen below.



So by the bolt coming loose it caused the pump to sieze up. So I took it apart and replaced the bolts with new ones and it ran like new but now I have this problem to deal with.

So THAT is why I believe that it is a blown head gasket but I wanted to hear someone else say it without actually hearing my whole story and just making assumptions