Last weekend I took my 97XJ up Hells backbone in southern UT with a military jeep trailer. Just before I reached the top I got this warning sound from the dash with the check gauges light on. I then notice my temp gauge is in the lower end of the red zone and so I pull over and with in a minute the temp drops down to 220. I drove on a few more miles to the camp site. Oil pressure was low when it was overheating, but it has returned to the normal 40 when under load and 20 when idling.
What damage could have resulted from hitting the red zone?
I now hear what sounds like knocking or dieseling. I had gotten rid of this same noise about a month ago after changing MAP sensor, spark plugs, wires, engine oil, transmission fluid and transmission filter. I don't know what change made the difference but it went away. Now this sound is back.
Since then I have changed the oil and I will be changing the thermostat this afternoon.
What damage could have resulted from hitting the red zone?
I now hear what sounds like knocking or dieseling. I had gotten rid of this same noise about a month ago after changing MAP sensor, spark plugs, wires, engine oil, transmission fluid and transmission filter. I don't know what change made the difference but it went away. Now this sound is back.

Since then I have changed the oil and I will be changing the thermostat this afternoon.