JMason

Hello everyone this is my first post on the forum.
have to say this is an awesome place lots of great information

So I have a problem with my Cherokee.
Its I have already viewed a few posts pertaining to what I think may be my problem but I wanted to start a thread particular to the the vehicle's symptoms. Maybe some of you experts could shed some light on the novice?

Here goes. I've had some heating issues in the past, heater blowing cool air. About 5 years ago the Jeep overheated, a cracked radiator ensued and it was subsequently replaced. It has threatened to overheat on at least two other occasions since then. I have recently (within the last two months) did my own coolant flush and attempted to backflush the core. The second occasion of threatening to overheat happened today.

From my explorations on this site I am presuming its the heater core. I'm not sure if it needs replacing (geez hope not) or if its just clogged up and pushing gunk into the thermo and screwing that up? With all the smart folks on here, what would be your takes on this situation? Would one be able to tell by the symptoms described whether or not its cloggy or if it simply needs to be replaced? Would clog screw up the thermo?

I'm a beginner in the mechanical side of Jeepdom !

Fred/N0AZZ

You have to remove the thermostat to do a flush then replace it with a new one also a new radiator cap.


The Water Pump and Fan Clutch are both suspect also and. all should have been replaced when you did the radiator. You are using a cleaner when flushing the cooling system aren't you?


If you didn't get the core clean it may well have clogged up the radiator again a new radiator is only a $100 at AutoZone with a lifetime warranty if you need another but replace the rest of the system once clean and you should be good to go.


Its one of those things that XJ's of this age just need to have done.

Firestorm500

Low heat in the winter could be a clogged heater core, low coolant, marginal water pump, low engine temp due to bad thermostat.

Overheating and cracking radiators will not be caused by a clogged heater core.

Replace all cooling components except heater core with quality replacements.

If you can pour water through the heater hoses and it goes through the core and out the other hose, the core is not clogged.

If, after you do everything to your cooling system and it still runs hot, suspect blown head gasket and/or cracked head.

JMason

thanks for the info guys

theres a local mechanic that is pretty good, hes got a '96 hes done this kind of work on. ran by there today to speak with him and make a tentative appointment. just not sure its work i could do as i am still learning that side of things but trying to learn as much info as possible. i could attempt it but then again i dont have the tools to cleanse that system.
the mechanic told me that its wise to cleanse these XJs about every 3 years because of their notorious problems in that area. mine has been neglected on that front, ive done at home coolant flushes but thats it nothing deep. i did use a chem treatment when i did the flush.

i believe the water pump was replaced when the radiator was, i guess ill find out soon enough.

im going to talk with him about some of the things you mentioned.
thanks again.

Orlo

I think you're on the right track. If you have a trusted mechanic who knows these machines you will be ahead of the game to have him assess the issues. I've seen others on here with less than beginner skills try to wade through this maintenance and end up botching it.....despite dozens and dozens of posts from helpful experts. This forum is useful for knowledge whether you turn the wrench yourself, or choose to deal with a mechanic from an informed position. Let us know how it turns out.

InitialForce

Just my 2 cents, when my radiator cracked on my 01 both the waterpump and fan clutch turned out to be bad as well

greenpaint

I to would suggest change tstat, pump and viscous fan all at the same time. There all fairly week links in a very important chain!

InitialForce

I'll just leave this here. That's out of my 01

Robert_B

Looks familiar.....

Firestorm500

That one's in decent shape compared to some that I have seen.

JMason

so a little update for those interested,

took it to my mechanic.
the heater coil was definitely funked out. he flushed the system. the thermo was broken not opening all the way so he replaced that, and also put a new fan clutch in it.

he told me there is quite a bit of rust coming from inside the system and that the radiator is probably collecting a bit of it on the bottom. he recommended at some point taking the radiator out and turning it upside down and getting the stuff out of the bottom.

also said that the next thing that will probably go are freezer plugs, so with that in mind i'm going to pick some up and do it myself.
and also he mentioned that the head gasket are something to watch.

what is your guys opinion?

jeep seems to be working okay now.

once again thanks for the info and the help.

InitialForce

You can't change all the freeze plugs without pulling the motor. Aside from that, that's not something I would change unless it's leaking or popped out. And especially not before pulling the water pump and checking it... the pump impeller is made from steel. I can almost guarantee you that most of the rust came from your water pump impeller disinegrating.