Cooling woes: 88 4.0l

[woody]

Jeep is fairly new to me, but until yesterday it's 'habit' was to run at 165* -/+ while moving, then shoot up into the red upon decel or at a stop. During continuous highway-speed runs, it stayed glued at 165*. I swapped out hoses and a thermostat (180*) but this changed nothing.

Yesterday it went hot on the way to work, and I uncapped it to compare the gage reading to our lab thermometers (gage is accurate) Lots of coolant loss then so I refilled and went home...seemed to run hot (hotter than it had been) and this morning got NO heat out of the vents, where before heat was always strong.

Thinking of replacing the bottle, put in another thermostat (195*) and replace the fan clutch and possibly the water pump. I called the parts house, and they list two clutches, a thermal or non-thermal (non therm is in stock) any clues to tell which one I want? and refresh my memory if we have to pull the radiator to swap the clutch. IIIRC (3 years ago) I did a waterpump on my MJ and I pulled the radiator for access, unclear if it was to pull the fan or the pump. If I have to tear it all open, I'd be stupid NOT to put a pump in, I think...

Any advice from the experts?

 

[Eagle]

Symptoms are those of fan clutch. The thermal is the heavy-duty -- non-thermal works, but makes more noise and doesn't have quite the ultimate capacity of the thermal.

Lack of heat indicates low coolant level -- pushing air through the heater core.

 

[woody]

"Lack of heat indicates low coolant level -- pushing air through the heater core."

That's what I was thinking, since that came up after introducing lots of air in when I pulled the cap...and I didn't properly burp it...just added more coolant to the empty bottle.

Will burp & see...

So thermal sounds like the way to go...pull the whole front apart for a clutch replacement or just a tight squeze with the rad in place?

 

[Eagle]

Get the "right" heavy duty. Autozone is too deep. Delco or (I think) Hayden should fit right.

Somebody posted they got the "right" one from Carquest,.

 

[woody]

Well after one trip back (they gave me the totally wrong one) the Auto-Zone TorqFlo #215101 was a snug install, but did go in w/o pulling anything but the shroud and some skin off one knuckle.

This PN crosses with TorqFlo 922625 Hayden 2625 and Four Seasons 36980 and was $38.00 BTW.

I burped the block well, and all seems good to go. Still runs a little cooler than I am used to...175* or so (shouldn't complain) but the overheating problem didn't appear (yet)

Thanks for the advice Eagle!

 

[AZ Jeff]

Get the "right" heavy duty. Autozone is too deep. Delco or (I think) Hayden should fit right.

Somebody posted they got the "right" one from Carquest,.

Eagle--minor point for future reference: the Autozone one IS deeper than the OEM Delco unit, but WILL WORK if you upbolt the top rad. core support and tip the rad forward during the install. Once it's in place, it clears the rad just fine. It's just a bit long to fit over the studs with the rad bolted in place.

 

[Eagle]

Eagle--minor point for future reference: the Autozone one IS deeper than the OEM Delco unit, but WILL WORK if you upbolt the top rad. core support and tip the rad forward during the install. Once it's in place, it clears the rad just fine. It's just a bit long to fit over the studs with the rad bolted in place.

If it's that tight, I don't think I'd want to combine it with a transfer case drop