> Vehicle is a 2001 Cherokke, 4.0
>
> Problem: I start the vehicle and bring it up to operating temperature (gauge
> reads between 190/210). Heat in vehicle works fine.
>
> On two occasions I was driving along when a warning chime sounded and the
"Check
> Gauges" light came on (I had been driving for roughly a half hour...outside
> temperature was in the 20's). I looked at the temperature gauge and it had
shot
> up all the way into the red zone (260). The first time it happened I pulled
> over, shut the engine off, and checked under the hood. I didn't notice or feel
> anything that would indicate the engine over heating... no excessive heat,
> steam, odor, or "pinging". I restarted the vehicle and the gauge dropped back
to
> 210.

perhaps you have an air pocket in the cooling system!

> A couple of days later, it happened again; only this time the "check gauges"
> light turned off and the gauge dropped back to 210 before I had a chance to
pull
> over (fortunately this time it happened I was about 100' from my driveway).
> Again, no observable symptoms of excessive overheating.
>
> Once I was able to check things more closely, I noticed that the upper and
lower
> radiator hoses were warm to the touch, and there was no pressure and very
little
> coolant in it. The radiator and cap were just barely warm.

still under warrenty? -- I recommend to take vehicle to the dealer and have them
deal with it! >> a common Jeep issue!

> There's no sign of any fluid leaks or lost coolant. The level in the expansion
> tank hasn't gone up or down. The electric fan has kicked in a couple of times,
> but the gauge was still in the safe zone (about 230).
>
> I replaced the thermostat (195), and it's still running the same way... engine
> warms up, heat is fine, but radiator, upper and lower hoses are barely warm.
>
> What could be the problem here? Weak water pump? Clogged or blocked hoses
and/or
> radiator?

air pocket!

> FWIW, the outside temperatures here have been in the low/mid twenties.

that's nice

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BBA
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