Hey guys, I've got a 2000 cherokee with I6. The other day I was driving along and noticed my jeep was running hotter than normal. The needle was at the 3/4 hot mark. I kept on going ( about 5 more minutes) and about 1/2 mile from my house it went into the red. I was stupid and continued to my house. By the time I got home the motor was rattling like bad bearings. It was very hot. Oil smoke coming off valve cover etc.

Any way I let it cool down and started it up and the bearing noise is gone but if I stand at the back of the truck the exhaust sounds like I've got a cam-idling pretty rough but is still driveable. The service engine light is not lit.
I have checked the oil and it doesn't look milky. No steam from exhaust. How do I go about trouble shooting this? Could I have just burned a plug or maybe the coil got to hot?

As far as the cooling system goes I'm gonna put in a new thermostat, waterpump, and flush all the rusty red liquid out. Hopefully that fixes my overheating.

Thanks for any help. I'm really hoping my head gasket isn't blown. Do these motors handle running hot good or no? Keep in mind it was run very hot.

Sorry for the long post but I just want some opinions on what check. I don't wanna replace parts that don't need fixing- I am broke. thanks

 

Does the engine run smooth? Do you have any missfiring (sometimes they wont throw a code)? Doesn't sound like you dameged the head with no water in the oil and no white exaust. What about the water, does their appear to be any oil in the radiator, bubbling or anything abnormal other than the afformentiond rust?
BTW welcome to cherokeeforum!!!!!
edit: with that odd exhaust note, you could be looking at an exhaust valve.

 

Pull the oil fill cap off and look down between clyinders 3-4 and see if you see any green might be a slight crack if not the head should be good,next is a commpression check and so on, good luck.

 

thanks for chiming in. The engine's just missing a little a bit at idle. When sitting in the driver seat it seems to be shaking more than normal and the exhaust is pooting (can't come up with better word to describe lol). If this motor does not have any damage then i'm sold on jeeps cause I ran this thing very hot. Motor was rattling bad when I finally parked it but after it cooled down it fired up and it went back to sounding normal- just sounds like its got a burnt plug or something... I don't know?

 

you pull the dip stick after u ran it again?

 

Yeah I've run the jeep in the yard after it ran hot. Probably ran for about 10 minutes before it started getting hot again. Oil still looked good.

Also I'll look through oil cap in valve cover tomorrow for coolant but my coolant is so rusty red I don't know if I'll be able to notice it.

Thanks for the help

 

Time for Ye Olde Compression Test.

 

x2

 

x3 on the compression test. I know a friend of mine has a Ford Explorer with the 4.0 V-6 (btw, NOWHERE near as good as the AMC 4.0 I-6 lol) and he had rough idle due to coolant leak. But here's the trick.. he didn't have any coolant leak or severe 'milky oil'. The way he had it tested was through the coolant in the radiator with some device that had fluid which changes color when exhaust is allowed to mix with coolant.