On Aug 25, 1:46*pm, wrote:
> I love my Jeep. *I've had it since I drove it off the lot new. *That
> was 140k miles ago, and it still looks and runs nearly the same as my
> first trip...Except
>
> The last few months it has been running hot once in awhile. *It is
> generally on very hot and humid days, but in the past it handled them
> fine.
>
> I suspected the thermostat, so I replaced it and the housing, power
> flushed the cooling system (it needed it). *It seemed to do the trick,
> but then again it cooled off outside so probably was a coincidence.
> It happened again.
>
> I checked the fan clutch and it seems fine, I cleared out the radiator
> fins, checked tightness of the S-belt. *All good. *I am thinking maybe
> it is the sending unit, because the way it overheats is very odd.
>
> It will go up to 210 and just sit there like it is supposed to. *When
> it overheats, it doesn't just gradually increase, it snaps up to just
> under the red line and the "Check Gauges" light comes on. *Then a
> couple minutes later it will snap back down to 210. *Then a bit later
> it will snap back up again to under the red and then snap back down.
>
> No noises or noticable changes in performance. *I was wondering if
> this is some kind of computer symptom of something else overheating,
> but I can't find anything on it anywhere.
>
> Any ideas?

I think a loose connection on the sender can act like that, you might
want to give it a clean to see. It is on the back top corner of the
head. I think the gauge pins hot with no connection, but could be
wrong.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com