Today I drove my 2001 Jeep XJ home, and although it felt a little sluggish, I didn't think of anything other than it needed a realignment as I replaced the tie rod ends. My wife drove it later this evening to the store and called me saying it had a light on that said "check gauges. She sent me a picture and surely enough the volt meter was all the way to the left at 9 volt. She came back, turned it off and let it sit.

Later this evening I started it up, and noticed that when I turn on the A/C, the volt gauge dropped from 13.5v to 11.5v. I drove it up the main street and noticed that not only the volt gauge suddenly dropped to 9v, the water temp did not wanted to go down. I brought it home, let it idle and check if I could find anything. Suddenly boiling coolant came gushing out of the reservoir so I turned it off and let it sit. I decided to check to oil lit as well and.......noticed green coolant as well.

So, assuming that the high temp blew the head gasket, I am still trying to figure out what happened. I need this Jeep to run by Monday and could use some ideas so I can fix her up.

My thoughts: at first I thought the alternator, as it looks like the original one is still on it, but why did engine overheat while the fan was running? Water pump too? All these parts could go at the same time?

So, please share your thoughts so I can make an effort to fix up my Jeep as it is my daily driver.

Thanks!

where was the green coolant? in your oil? any smoke coming out of the tail pipe?

of course you have a 0331 cylinder head so overheating is not a good sign. If you have coolant in the oil, sounds like maybe another 0331 cracked head.

That's not going to happen. Face that fact now and plan accordingly.

At the very least, you are going to be replacing the head gasket. Since it's a 2001, you are probably going to be replacing the head.

You might even be replacing an engine.


My guess is your wife didn't notice the temperature gauge was screaming "Stop the car!", and trashed the engine.


Check your belts. You probably lost a belt, thus were not charging or turning the water pump.

is the drive belt still on the jeep? a slipped belt could cause the alternator to stop charging and the water pump to stop pumping. if one of the pulleys is seized could also cause similar symptoms.

IF you have coolant in the oil i dont see how you get it running by monday unless you have a machined head and gasket set laying around. sorry.

has your poking around turned up anything else?

Well, wife called as soon as the check gauges light came on. Temp was not an issue at that time. I guess I will be taking the head off and see what's there. Can someone tell me where the crack typically is?

where is the "like" button?

typically between cylinders 3 and 4 on top of the head. Open the oil cap an look inside with a flashlight, or take off the valve cover.

if you rent a pressure tester you can pressurize the system, and with the valve cover off you would see bubbles coming up from the head.

Ok, so a quick update on this. I decided to take everything off so that I can take the cylinder head off. The thermostat is totally stuck in there, and I can see that the oil is mixed with the coolant based on the color of oil that sits on top the bolts inside the cylinder head.

Planning to take a close look at the head and see if I can find anything wrong with the head. Other than that, I bought pretty much everything that has to do with coolant. (water pump, thermostat, hoses, etc).

The drop in voltage as I mentioned in the older post might happened due to the cooking coolant spraying on the alternator.

Hopefully the engine itself is not ruined, otherwise I have to make a decision to keep this orange XJ.

Check the head and the bearings BEFORE you install any of those new parts.

You do have that decision to make, and you might just be returning them.

Thanks very much for getting back to us.

Here is a pic of how it looks like when I took it off.

Rebuild.

is that cylinder scored or is that a reflection

Yeah, that is just reflection. The walls look like new. However, here are few other pics of the parts after I removed them.










That thermostat was completely toast. I wonder if that could have been one issue as that can't be good......

any cylinder that got coolant in it will look like new. it's tough to judge from a couple pictures. if the oil looks anything like that gom on the deck of the block it needs rebuilt.

good luck.