2000 Cherokee / Blown Head Gasket !

Hello - Have a question and maybe someone can shed some light on this .....

Saturday night my wife called and stated that her Jeep overheated and she pulled off ASAP, she did not drive it when it happened, she noticed the increase in the temp guage and pulled over, opened the hood and the anti-freeze was leaking out from under the front of the motor ... She had ot towed to a local garage we have dealt with for 5+ years, they checked everything and stated that they found CO2 in the Anti-Freeze or something along those lines .... Said it looks like a HEAD GASKET is blown !

She takes the utmost care of her Jeep and only has 55,173 miles on it ...... That is the weird thing about this problem ...

Is this normal ? it has the 4.0 engine in it .......

Thanks,

Bill

Hello - Have a question and maybe someone can shed some light on this .....

Said it looks like a HEAD GASKET is blown !

She takes the utmost care of her Jeep and only has 55,173 miles on it ...... That is the weird thing about this problem ...

Is this normal ? it has the 4.0 engine in it .......

Thanks,

Bill

I have a 2000 Cherokee with the 4.0L. It has 69,500 miles on it. I have taken extremely good care of it as well. It runs excellent and always has. What you are describing is unusual. I had a 1994 Cherokee with the 4.0L and drove it hard up until it logged 122,000 miles on it and traded it in for the then new 2000. It never overheated even though I had it in the desert a lot. The 4.0L is a good solid engine.
I have never experienced an overheat in either of my Cherokees so I do not know how easy the head gasket blows. the trick is to shut it down when you see the needle move past 230 degrees, but why did it overheat in the first place? Have you kept the antifreeze flushed and re-filled? Do you live in a hot and dusty desert? Did you buy it new? You've got me on this one. I would just fix it and go on.

tb

What did they find in the coolant?

Sounds more like a water pump. I'd have it towed elsewhere and get a second opinion.

Good Morning,

Got a call last night after work from the garage. Here is what they are saying so far .....

They did a pressure test on the engine and nothing leaks, so it is not a Blown Head Gasket as they first thought.

No hoses are leaking and it is indeed holding the anti-freeze. He mentioned yesterday morning that they detected CO2 within the anti-freeze, so that is why they pulled the plugs and did the pressure test.

They test drove it for awhile to see if it overheated again and it did not overheat. I mentioned the water pump and he told me that was fine, no leaks !

This is very strange ........ Here is what they are doing today (Wednesday ) - He plans on driving about 80 miles straight on the highway and some various hills to see what happens ..... We live in South Central PA, normal climate, no high heat and the average temp. outside is 65 to 57 right now .....

Here is a quick history on this Jeep and anouther issue that has happened. We purchased it used from a dealer who has a good reputation, he goes out and buys Chryslers / Jeeps / Dodge from some auction house, these vehicles from what he stated come in off lease and then are gone over and sold ...... This jeep was in outstanding condition when purchased about 3 years ago, never had a problem with the exception of this:

This past winter my wife said that her heater was not blowing that much hot air, it was kinda lukewarm, not the normal hot air coming out, if you look in the radiator it looked all dark and dirty, we had it power flushed, that did correct the problem, the garage said that when they flushed it, it was very dirty and kinda think and sludgey ..... The heat blew hot air and then about a month after that service was performed, it went back to being lukewarm, we took it back and they did the same power flush, anti-freeeze looked horrible ! I did check right after they did the first flush and it looked great, fresh, clean anti-freeze ...... so they did it again and the heat came back .....

He is puzzled why so much sludge is being created ? They did change the thermostat ........ Anyone have an idea what this might indicate or be causing this to happen ?

When we bought the jeep, it had 22,000 miles on it ........

I will update you later when they call ...........

Good Morning,



He is puzzled why so much sludge is being created ?
When we bought the jeep, it had 22,000 miles on it ........

I will update you later when they call ...........

You really need to do more than flush the radiator. You need to backflush the block as well. I would guess that before you the Cherokee never had any maintenance performed on the cooling system especially if whoever had it was leasing it and planned to turn it in anyway. The sludge must be coming from an internally dirty block. This is not to say you got a bad XJ, but the cooling system is too often the last thing people maintain even when they are really good about the easier things like changing the oil. Take it to a good radiator shop and get the radiator and the block flushed out until the water comes out clear.

tb

I have own several Jeeps and work on alot of them. I have ran my own Jeep very hot on the beach and never blown a head gasket. The 4.0 's are greta engines. If they did a power flush you should have gotten a good flush job. But it can't always get it all out. And the radiator is alumium and doesn't clean very well. Sometimes it is better to replace the radiator. There are other things to consider but may not be require but there is the fan clutch to check also. Radiator cap even the ones on the expansion tank models. Everyone should at least do a drain and fill on the coolant once a year.

If they found Co2 in the antifreeze then that would indicate that exhaust gases are getting in there somewhere. If its gunking up like that then the coolant is mixing with something to cause it. Is there coolant in the oil? Could be that the head is rising slightly upon acceleration or long trips - head bolts loose?????

If the heater isnt blowing hot air then thats a thermostat or heater valve problem.

Could also be that the tranny cooler built into the radiator is leaking causing tranny fluid to leak into the coolant - check your tranny fluid for signs of coolant.

i think they meant CO,since Co2 is carbon dioxide,the stuff you exhale so unless someone has been breathing in your radiator

Sounds like the radiator or the water pump to me too. My cherokee is a '96 with 150K on it.
I've had every typical oil leak there is, but the head gasket is still good to go.