Overheating? Quick help please.

[UltimateG]

Hi.



I had a problem with my engine overheating today. I’m hoping someone smarter than me can tell me exactly where the problem lies.


The Jeep: 1994 XJ. All stock. Runs great, and never any history of cooling problems. I am pretty sure the coolant mix is roughly 50/50% water/EG. (But I may be mistaken about that). The radiator, water pump, and hoses are all newer, and have all been replaced within the last 7 years / 40,000 miles.

The setting: Weather has been very cold. Temps were -5 degrees Fahrenheit this morning. The Jeep has not moved in the last four days.

The situation: This morning when I started her up, everything seemed normal. A couple miles down the road, (~10 minutes) I noticed the temp gauge was getting high. It just kept climbing, and didn’t stop at 210. The needle kept going up to the red zone. Once she got close to 250, I turned off the engine.

This entire time, the heater was blowing completely cold air.

I looked under the hood, and there was a little bit of steam & water coming out from the radiator cap. Everything else looked okay.

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I let the car cool down for a few hours. Then drove it back home. Everything seemed fine. The temp gauge stayed below 210 the whole way back.

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So, where exactly in the system did the malfunction occur?

Thanks!