Please help...bad overheating problem!

· I started the Jeep this morning for about 10 minutes to let it warm up. It had been outside overnight (15 deg. F). It was at operating temperature after this time, but the heater was blowing cold air. I backed out of the driveway and heard a popping noise from the rear end. I had also heard this noise the day before.
· About two miles down the road, the temperature gauge went as high as it could go, the check engine light came on, steam was coming out from under the hood, and there was a popping sound like someone knocking on a door coming from the engine. The heater was still blowing cold air.
· The engine just about stalled in the middle of the road, but I was able to park the Jeep in a parking lot, turn it off, and look under the hood. There was a burnt rubber smell, and the overflow bottle was boiling over and spilling coolant everywhere. The upper radiator hose felt like it had pressure in it, but it was cool to the touch. Coolant was leaking out from where the cylinder head gasket is.
· After a few minutes, I tried starting the engine again. It had cooled down to normal operating temperature, but after about a minute, the temperature gauge was at maximum again, steam was coming from under the hood, I heard the popping sound again, the check engine light was on, and the engine stalled out.
· It should also be noted that on the day before, the heater was working properly, and that the radiator was replaced on this Jeep at approximately 55,000 miles when I bought it, but I don’t know why, or what else was replaced along with it.



What do you guys think?

Improper coolant mix, bet it froze, check your freeze plugs, they might be gone.

Rich, it's been out on cold nights before though. Maybe it just took a while for them to come out? I'll have to check that.

Forgot to mention...2001, 4x4.

this is a sad story- but its happened before...its the ending that no one wants to hear.

I`d guess what happened was either the thermostat stuck, or like Rich said- the mixture of coolant to water was off, and you got an icedam somewhere inside-probably in the upperend of the engine. The first clue would always be no heat- no heat means the `stat is stuck, or theres a blockage (among a few other things)- the second clue is that upper hose being cold. A cold hose after warmup is a bad sign. I`ll trump your 15degrees with my 9degrees, an i aint gonna start my until it hits 20. That 50 weight oil in mine is probably like frozen peanutbutter.

The bad part you mention is coolant comeing from the headgasket- Im thinking you mean midblock where the head joins the block? Thats bad. Assume your going to need a new headgasket at the very least. Hope you dont have a fried block- warped head- scoured pistons- much less a hole in the piston wall (s)- hopefully you didnt let it run very long when it was way hot. It dont take long to bend metal when it gets that hot an toasty.

Check the oil first- if its that milkshake special blend of "brown frothy"- or the `ol lime green and oil look , prepare the engine hoist- its gotta come out....

If not.....

Time for a compression test. I`ll guess your headgaskets fried and cracked at the least.

I wish you the best of luck. these engines can take alot of abuse- its just a matter of "did I catch it in time....this time".

What do you think the banging noise was, and why do you think it stalled out?

Good thing I have an 80K powertrain warranty! I probably drove it for about a minute or two after the gauge spiked. I couldn't tell how much coolant was coming from the gasket, but it was coming from under the area where the injectors and intake manifold are. There was lots of steam coming from there. I didn't check the oil, but I will when the tow truck shows up today. Could have been freeze plugs too, but I don't know.

The bang could have easily been hydrolock cause by a bad head gasket. Hope not.

Anyone else?

Hate to bring up an old thread, but Mine just did the same thing tonight..... Everyone will know the verdict tomorrow.

Really wish I'd remembered to put more coolant in before the cold weather came.....

Anyone seen a completed diesel swap that still used the AW4 and had AC?

just finished mine but in my case the rear ( engine block ) freeze plug rusted through and caused my problem. total parts/machine work was about $700 including new exhaust manifold. if ya gotta pull the engine fix all you can while its out! good luck.

Block seems to be fine now. Radiator is leaking, and I finally got heat from the heater core. I've been firing it up and hit 210+ almost hourly all day to help circulate the coolant. I'm sure the heater core is shot, so I'll be looking for right ups on how to replace it and the radiator, and if someone has a heavier duty radiator (looking to turbo the jeep this spring once the LS1 miata is done)