Death of a 4.0

[cedrick]

sorry about the engine, but the kung fu bit I wasen't expecting allmost blue popcorn all over the keybord ,thats funny, painful, but funny

[car-15]

your radiator was frozen.
Happens a lot in real cold temperatrues
The motor starts, it gets all warm, but it can't get into the radiator because it's still frozen and nothing heats it up
then you burn it all off as you blow the head gasket.

You'll have to mill the head and deck, for sure they are warped.

+1 just what I was thinking

[Atrain]

Probably right about the frozen radiator. Something was frozen and prevented circulation, thats for sure. I didn't plan on being out in that temp, but that's CO weather for ya. I'll take a blown motor over going out "The Shining" style on the side of the road.

[HunterCO]

The piston started to melt and the others did not it has nothing to do with a "Frozen radiator" (sorry that made me laugh my arse off). I bet the muffler bearing went bad and that caused the whole problem. [roll]

Look at the exhaust seat in the head and see if it has a crack. That is not what caused it but usually if you get any cylinder that hot it cracks the head.

[Atrain]

I only posted one piston, there were more of the same. Something in the coolant system froze, I'm sure of that. I'll replace the thermostat and flush the radiator. I'll check the piston return springs while I'm at it :mrgreen:

Here is piston #5, gotta love those metal flakes sitting on the piston:

[HunterCO]

Trust me nothing "froze" but believe as you wish. :mrgreen:

[Atrain]

I'll believe what I know, that something prevented cooling. I know about cars...what sub zero temps do to them, I'm just starting to learn about.

[XJ]

Someone always has to joke about the "muffler bearing", but that used to be an actual GM part...a reinforced rubber donut for supporting the exhaust system.

Is this 4.0 from back when they had the pressurized cooling system with the plastic tank and vacuum-operted diverter valve?

[Atrain]

No, it's a 2001 XJ.

[HunterCO]

I'll believe what I know, that something prevented cooling. I know about cars...what sub zero temps do to them, I'm just starting to learn about.

I was just poking fun of you. You got that thing hotter than hell. [wink]