heater

been having some issues with my 92 xj, it takes forever for the heater to heat up in the mornings. like 15 minutes of 45 mph driving. now at night it seems to heat up in about 5 mins top. my question is, i never got a manuel for the heater. so ive only used defrost(far right) heat(one to the left of heat) and then vent. im wondering if the 3 settings under (Air conditioning) are really duel purpose, and would maybe help me heat up faster.

Ive flushed the cooling system out, the inlet hose to the heater core gets hot fast, but the output stays cold for a much longer time. the vac hose going to the control unit seems to be working.


Any ideas?

sounds like the heater control valve is stuck

Have you checked the return line form the heater core to make sure its getting warm as well? There may be a blockage in your heater core not allowing the warm water to flow through it properly.

"Have you checked the return line form the heater core to make sure its getting warm as well? There may be a blockage in your heater core not allowing the warm water to flow through it properly."

Xjcj3a said:

Ive flushed the cooling system out, the inlet hose to the heater core gets hot fast, but the output stays cold for a much longer time. the vac hose going to the control unit seems to be working.

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He mentioned that. Check to see if there is a difference in the position of the lever on the valve with heat on or off, or better yet have someone turn the heat on while you're watching the valve to see if it moves at all.

My 90 has always taken awhile to get hot, but when it does, it's HOT. I made the switch to an open system so I have all the same heater parts as a 92. The valve seems to be a weak point (funky plastic part). I'm contemplating just doing away with the valve altogether and running straight hose to the core like the later models.

Where are you feeling the hose? Before the heater control valve or at the firewall connection. If before the valve I'd think X2 on the valve. If at the firewall I'd say you still have an issue with your core.

The controls for A/C don't do anything for the heat but the defrost should kick your A/C compressor on to remove moisture from the air. Also what temp is your T-stat. Seems like a cooler t-stat would make things take longer to heat up

Try putting it on "vent" with fan on high. Seems to move more air.
OR
Turn the heat on WITHOUT turning the fan on to let the core heat up before passing air over it.

ParadiseXJ said:

He mentioned that.

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Opps. I took that statment to mean the air output from the heater was still cool.:dunno:

On my 89 I had the same problem both before & after going from closed to an open system. I did away with the heater valve and installed a ball type valve. In the summer I close it, in the winter I open it. Seems to be working fine.