Burp Tank went BOOM!!!..Explosion inside

[hppwdn]

So I have a slight issue with my cooling system.

A couple weeks ago I pulled into a parking lot after driving for awhile. I sat with the car idling for awhile with no problems. As soon as I turned the car off BOOM. A big bang and then smoke everywhere. Also coolant everywhere, which meant at least I wasn't low on coolant. It turned out to be the radiator hose coming off the tstat housing. The house literally exploded.

I replaced the hose and all was well. The next day I went for a fifteen minute drive and when I stopped the car, BOOM again. This time it blew the hose off. So I removed the tstat hoping that was the problem. In florida it's pretty hot and the tstat isn't very essential to warming up. Both of these times the temp guage was fine, but there was a ton of steam after the boom.

Now a couple weeks since then with everyhitng being fine (still no tstat) a new problem arose. I was sitting in a drive thru and all of a sudden I see some spoke from under the hood and I look down to an overheating gauge. As soon as I press the gas to move to a parking space....BOOM. I pop the hood to see the entire top of the burp tank had blown off (little black thing the radiator cap goes on on the driver's side). Rather annoyed I finished my food letting the engine cool down, patched the tank as best I could and drove a mile home.

I changed the burp tank out with another, changed the oil, changed the coolant and let the engine run for about 20 minutes while cleaning up. I didn't get to see the gauge, but right as I was about to leave there was another BOOM. The top blew off again.

I'm fresh out of burp tanks now and looking for a cause to this problem. What could be causing this? It drove fine for a couple weeks so I have my doubts that the radiator is not efficient or the coolant hoses are clogged.

Any Ideas? I have a couple brewing around, but wanted to see what you guys think.

The water pump was replaced at the motor swap about 12k miles ago.

[DigitalJesus]

Sounds like you need a new radiator cap. At 14lbs it is suppose to release and let the overflow out to the overflow tank by your battery.
Also when filling your coolant are you taking both of the caps off the cooling system, and then filling it. That is what properly bleeds the air out of the system.
Other then that it could be many other things. But hey you got to start somewhere.

[stinkyP]

Like he said the excess pressure is not being released. If it's overheating you should see steam comming out of the overflow tank.

Is the coolant circulating ?? Maybe the impeler on the water pump broke off the shaft. Also a leaky pump (or any other leak) will cause the level to go down enough so it's not circulating and producing a lot of steam. That's what mine is doing, but it never blew anything.

[quagmire]

Uh oh, it sounds like you may have a bad head gasket. I'd suggest you do a leakdown test on the engine to figure out which bank is leaking.

[showngo]

doesnt sound like a head gasket at all. but somthing is causing a build up of pressure or a non release of pressure. like it ws said swap out your rad cap. and then check your hoses then if that doesnt work try checking your rad.
this is a weird problem though lol

[ouch1011]

Start simple and go from there.

As others have said, the radiator cap seal is spring loaded and is supposed to start venting pressure at a certain point (14psi sounds about right). The fact that you keep blowing shit up indicates that the pressure cap isn't doing its job. Replace it, see what happens.

Now, as quagmire (heh heh, alright!) said, it *could* be a headgasket allowing combustion gases to pressurize the cooling system, but I would keep that as a last resort, since head gaskets aren't very common failures on these engines. If this were a 3.8L Ford, then I'd say headgaskets without a doubt

[hppwdn]

thanks for the suggestions. I'm hoping it's a cap. They are relatively new, but I'd be very happy if it was just a cap.

I got three burp tanks at the junkyard today too. So at least I have backups if it blows up again figuring out what's wrong.

[NickR]

In addition to checking the radiator cap, check the hose between the "burp tank" (air separator tank?) and the overflow reservoir. If that hose were blocked, the pressure could not be released, even if the radiator cap were working properly. (Normally, if you squeeze the top hose by hand, should should hear coolant flowing into the overflow reservoir, but if that hose is blocked, it won't.)

[hppwdn]

I checked that hose to make sure it wasn't clogged. Got caught up today and haven't had a chance to work on the car. Probably gonna work on it tomorrow AM. Maybe I'll have a resolution tomorrow.