Heat problems?!?!?!?!?!?!?!?!?

[budgetxjmcknight]

89 xj, runs great, heat is crappy. Takes about 20-30 min to defrost the windshield. When you cut it to heat it blows cold air but just barely. Thinking my vents are clogged up or something don't really know. Any thoughts???

[4.3LXJ]

If you have air, the vents are not clogged. It is your heater core. They get plugged up easily and not pass coolant through. So no heat exchanged. You can try flushing it or if that doesn't work it will have to be replaced.

[Carves]

Most likely the heater core as 4.3LXJ posted.

... altho ... anything that restricts the flow of hot coolant in the heater circuit ought to be checked out.

[Rayburne]

Could be the coolant flow control valve.

[budgetxjmcknight]

All very great suggestions, I did think the heater core may be clogged but don't know how hard it is to get to, being this is my first xj. I have done them on other vehicles though and know they can be nerve racking. So how hard are they on an xj, might as well replace it , it is an 89 so couldn't hurt to try. I do get air flow but high on my xj is like low on my wifes zj??

[budgetxjmcknight]

After reading how much is involved in the removal of the heater core, decided to try and flush it out. Took the hoses loose from the engine bay. Then took the water hose to it making sure I was going with the way of normal flow. I just kept at it until I was getting just as much pressure out as I was putting in with the hose. Worked great, unclogged the core and now I have heat again!!!!! I also pulled the blower motor and checked it. It was all ok, guess next i'll try to clean the vents somehow....

[XJ Wheeler]

Awesome man, glad you could avoid the task of that heater core replacement.

[budgetxjmcknight]

I am loving the ride to work now used to freeze my can to death, lol.