northernchap

Hi guys, new Jeep owner here!

I bought a Cherokee the other day and the heater wasn't blowing much hot air - the fans run, but it never warms up too much.

First job I thought - swap out the thermostat, easy enough - right? Well, it seems no because I managed to snap the housing when I refitted it.

I'm waiting for a new one to be delivered, but while I do - I had a lot of trouble getting to the lower bolt because of the serpentine belt. I could do it, but not easily.

How simple is it to loosen this belt to get better access? And how do I then tighten it correctly? I'd rather not mess with it if I'm going to cause problems but if it's pretty easy then it'd help a lot .

Thanks!

salad

On a 1994 you loosen the bolts that hold the power steering pump in place, it then rotates:



Regarding not warming up very quickly, if the thermostat is functioning properly the system is probably running too rich. Could be anything from a vacuum leak to the O2 sensor keeping it cool. Stock thermostat won't let any coolant into the radiator until 195 degrees.

However your fan clutch is probably toast anyway.

Lowrange2

When you say it never warms up... do you mean the engine or the heat?

If the engine is getting up close to 210 and the heat still isn't blowing hot then you need to flush your heater core.

northernchap

Thanks guys!

The issue was that the vehicle was running fine, but had no heat through the vents.

The temp gauge on the dash wasn't getting very high, not had a Jeep before so not sure what the correct level is but it was moving maybe one-eighth of the way (mine is in celcius but can't remember offhand what the reading is) - generally I expect cars to get to maybe 1/4 of the way or halfway depending on the gauge. I know this isn't scientific, just trying to explain why I thought maybe thermostat rather than just heater core!

I figured for 5.65 it was worth switching out the thermostat and at the same time backflushing the heater core and a few of the hoses as a first attempt. Shame I broke the housing, as that's now added 25 to the total!

I ran the vehicle for 350 miles in one journey and it did not overheat or go beyond the low level on the gauge, nor did it get hot at the vents, just warm.

salad

Temp gauge should be at the half-way point after a few miles/KM. Combined with your heater issue that suggests that it's running cold, but you need to verify that the gauge is accurate first. XJs prior to 1997 have two temperature sensors, one is a dedicated sending unit for the dash gauge and they're known for going out. Find an IR thermometer and point it at the thermostat housing on the engine for an accurate reading.

Firestorm500

If true engine temperature ends up being OK, then no heat is usually caused by a plugged heater core or blend doors not functioning properly.