Jeep gurus/Mechanics-heater trouble...

[Fjolnirsson]

This morning, my wife tells me the heater in our Jeep worked fine, blew hot air like always...
Tonight, I got in and drove to Walmart, didn't notice one way or another, so I assumed it worked fine. I came out, started the jeep and turned on the heater while I loaded groceries. Drove home. about 30 minutes or so total, and by the time I pulled into the driveway, the air had just barely gotten warmish. I noticed the engine temp was only 125 or so...
Tomorrow, I'm going to look for broken hoses, disconnected air hoses, and such, but do any of you have an idea of what the problem might be? It's a '97 Cherokee.

[dogmush]

Coupled with low engine temp it sounds like your thermistat is stuck open. 

[myrockfight]

Coupled with low engine temp it sounds like your thermistat is stuck open. 

That was my first thought too. If you have a hard time with anything, go to Jeepforums.com  In the appropriate sub-forum you can ask for help and there are plenty of people to give it. I went there all the time when I had my Wrangler. What Jeep do you have?

[Jamisjockey]

Coupled with low engine temp it sounds like your thermistat is stuck open. 

Agreed.  If its the 4.0, (should be the 4.0 for a '97 XJ) its an easy fix, thermostat is at the front of the engine.

[Declaration Day]

  I'll cast my vote for a stuck thermostat.  Funny you mention this, I'm doing the same repair today on my 4.0L Wrangler.

[Grandpa Shooter]

Thermostat!

[Brad Johnson]

Stuck thermostat.  Happened to me last year in the Vic.  Easy fix.  Probably time for new hoses and a system flush anyway.

Also, if the water pump is inexpensive and easy to change, do it.  That way you'll have a completely freshened cooling system.  It's cheap insurance.

Brad

[never_retreat]

Stuck thermostat.

[thebaldguy]

I had the same thing a few years ago. It felt like the heat just wasn't as warm as it used to be. It's really not too tough of a fix on the 4.0L motor. Replace the hoses and flush the system if you've got the chance. I have a 93 Cherokee and when I replaced the thermostat I replaced all the hoses and clamps as well. It's cheap insurance for your cooling system.

[Fjolnirsson]

Yeah, I pulled out the book on it last night, doesn't look too difficult. Still gonna take it to the shop tomorrow. I can do it myself, but right now I lack the time and a place to dispose of coolant. I figure it's worth $25 to spare myself the headache.

[myrockfight]

I've got a Factory Service Manual for a 2002 Jeep Wrangler. If you have a 4.0 liter engine, it will be of some use to you. The only thing that would likely be different in a Cherokee would be the transmission. You could at least take a look and see. It won't cost you anything. Let me know and I will email it to you as a .pdf.