98TJ Heat Issue

Always.... :)

Vac leak, possibly a cracked hardline or something that took a bit of heat from the engine to soften up and be able to seal. I'd check the hard lines running from the intake rail for splits or loose soft connections.

Although, IIRC the blend door is a stepper motor. In that case low vac would have just kept the output stuck to one setting.

If it's electrical or a stuck blend door (Guess if it got water in there it could freeze the rubber seals and make the door stick) Heat would then free it.

I'm out of ideas. :/

-- DougW

Might have just gotten some water in it, frozen enough to stick the door, later the ice melted and problem solved.

Hi Dave, Check the coolant level at the radiator, cold. Many times an air pock may fill the theater core. Those dried deposits should be back flushed out, every two years alone with the coolant regular change. God Bless America, Bill O|||||||O mailto: snipped-for-privacy@billhughes.com

If your thermostat is stuck open the engine won't make any heat. Happened last winter in my `69 4L XJ.

Riiight :) The regular coolant change :) That would be a good idea.

On the way home from work, it seemed to heat up normally, but I noticed a couple strange things that don't seem familiar.. when the engine warmed up, the heat was warm, but not hot . . but when I was moving, or even when I revved the engine, the heat would get hot. At the same time, I also noticed that when at idle, when the heat was not as hot, my oil pressure guage would creep up to about 40, and then when I revved the engine and the heat got hotter, the oil-pressure dropped back down to about 25 or so..

Multiple problems showing up here?

The frozen blend door is quite possible, as the entire jeep was encased in 1/4" of ice on Saturday night, and then an entire day of rain followed.. I will check the coolant, and keep an eye on the situation, and report any other strangities that show up.

Thanks for the help guys!

Sounds like low coolant.

Carl

Fatfingered. `96 XJ