Jeep Heat Problem!

TapouT

Well-Known Member
Joined
Oct 5, 2008
Location
Hickory nc
I have a '94 Grand Cherokee with the 4.0 in it. I took it wheeling last weekend and the heat hasn't seemed to work right ever since. It got pretty muddy where I took it. Before I took it the Jeep would almost burn you it got so hot. Now it just barely gets warm and it actually still feels kind of cool. Needless to say it was a VERY cold ride to work this morning. There's no water on the windshield/floorboard so I don't think the heater core is going bad. What could be the problem? It's full of coolant and the coolant doesn't look muddy at all. The Jeep gets up to operating temperature so I'm not sure if it's the thermostat? Could mud have got into my hoses and clogged it up? I'm going to try a new Thermostat and backflush the radiator. Any other ideas? Thanks for the help!
 
Simple- see if both heater hoses are hot and nearly the same temp, if not, the core is plugged. If they are both hot then you have a blend door issue inside the heater/ac housing.
If the coolant is not getting hot at all, then either you have a failed thermostat or low coolant level.

Diagnose before flinging parts at it. Lemme know if ya need more help.
 
the heater box needs vacuum for the doors to move. Check the vacuum lines!
 
Update: It happened again! My heat isn't hot at all. I ended up putting an autozone 195 degree thermostat in my Jeep yesterday, a day after I backflushed the radiator. It did fine last night I had all the heat in the world. This morning on the way to work my Jeep did something it's never done before. It was at a steady 160 degrees then it jumps up to 210 really fast and then back down to below 160 degrees and then it jumped back up to 160 and stayed there. My heat isn't working. What's the deal?????
 
Back
Top