No heat

[88pioneer]

Had a little bit of heat before my accident, but now have zero. I'm sure its probably a little low on coolant, but I would still have some heat. Changing the thermostat was an idea given to me, but not sure if that would help. I'm a newb to the HVAC system an don't know much :dunce: . Any help is greatly appreciated. :cheers:

[kyleag89]

Is your truck overheating at all? What temp does it run at?

[88pioneer]

Doesn't over heat one bit. Just did the open cooling swap. Need a new temp sender, cause mine isn't reading correctly, but I would say its sitting at 200/210. Everything works fine how it is, just not having heat in 30 degree weather sucks

[kyleag89]

If you have coolant flowing through the heater hoses then sounds like it might be your heater core.

[88pioneer]

I was feeling the same thing. Now to figure out how to replace it :typing:

[kyleag89]

Time to work in the most uncomfortable position ever... upside down under the dash! LOL I have never done a heater core in a MJ or XJ but I would think it is fairly simple like most Jeeps are.

[wannabeMJ]

fairly easy

most of the bolts are in the engine bay on the fire wall

your gonna have to work under the dash to get it out but its easyer to do it if you loosen the dash or just take it out

 

but first you said no heat but do you have air comming out (is the blower working?)

[88pioneer]

Yes blower works just fine, but never warms up

[Eagle]

Before you start ripping the dash apart, be sure the system is full. I don't know how it reacts with a converted "open" system, but the closed system stops delivering heat if the coolant level is even a little bit low.

[codymanche]

isnt 210 temp almost too hot i know a couple of my friends in az when they heat 210 we turn our e-fans on we rigged them to a switch so when we sit for a lil or whatever the case maybe its on and my old man said 210 is too hot. but i had a bad cap and started leaking coolent when i got to 210 replaced the cap and now i havent even touched 210 but i havent went hard in the dirt either lately so enough with blah blah is it suppossed to be 210 for opperating temp

[Eagle]

isnt 210 temp almost too hot i know a couple of my friends in az when they heat 210 we turn our e-fans on we rigged them to a switch so when we sit for a lil or whatever the case maybe its on and my old man said 210 is too hot. but i had a bad cap and started leaking coolent when i got to 210 replaced the cap and now i havent even touched 210 but i havent went hard in the dirt either lately so enough with blah blah is it suppossed to be 210 for opperating temp

210 is the normal operating temperature for a Jeep engine. 210 is NOT "too hot." There's a zone on the gauge that has a red background -- when the needle gets into the red, THAT's too hot.

[AmJay]

Don't know what year/engine your MJ is, but it could be a bad heater control valve or the vacuum connecting to it. I was also able to disconnect the heater hoses to the heater core and run a garden hose to it and flush a lot of junk out of the heater core. Using the garden hose you will also be able to tell if your core is plugged. If you can run water through it it isn't a bad heater core.

[Comanche County]

it could be a bad heater control valve or the vacuum connecting to it.

 

:agree:

 

Its on the passenger side firewall...follow the heater hoses and you'll find it. If the vacuum actuator doesn't work you can zip tie it open for a short term fix.

[88pioneer]

The heater control valve is brand new. Now i know where the core is, i'll try flushing it this weekend. I'll also check my coolant level. Thanks guys, hope it works :cheers: