[bmwmotogreg]

I have already bought a spare thermostat as the previous owner told me that the 99 4.0 will overheat from time to time. I have owned the truck for a couple months and it overheated for the first time tonight. I had been driving for about a half hour, everything was fine until it over heated. Have not checked the coolant level in a few weeks but is it possible that the thermostat was working fine and then closed up? or is it more likely that I should look elsewhere for the actual cause of tonights delay? :?:

 

[bmwmotogreg]

This may or may not be relative; The only reason I looked at the dash and thought something was wrong was that the air conditioning stopped blowing cold. Is this normal during an overheating situation or is this unusual? I am asking to see if this somehow disproves my "I need to replace the thermostat" theory. Any help would be appreciated!

 

[RRToadHall]

First thought is that it is never "normal" for a rig of any kind to overheat from time to time. If your rig is overheating from time to time you could have any number of issues to deal with. If your coolant level is dropping you have a leak. If you don't rectify the leak you will then overheat. If you don't catch the overheat situation you can drop a liner or fully toast/seize your engine.

I'd be doing a serious search and rectify.

 

[bmwmotogreg]

First thought is that it is never "normal" for a rig of any kind to overheat from time to time. If your rig is overheating from time to time you could have any number of issues to deal with. If your coolant level is dropping you have a leak. If you don't rectify the leak you will then overheat. If you don't catch the overheat situation you can drop a liner or fully toast/seize your engine.

I'd be doing a serious search and rectify.

I realize that overheating is bad and I do hope to get to the bottom of the issue soon. The problem is that I have had the truck for a couple months and this is the first time. I have read that the theremostat is sometimes at fault and does not always act the same which is to say an older thermostat can be tempermental. This will be the perfect excuse to drain the readiator and flush the radiator and start with new fluid.... At least that way I will have eliminated the thermostat as the potential problem...

Where should the temperature gauge sit on a 4.0? Mine is usually sticking straight up / half way to hot. I thought I remember reading a reference where it should be 1/4 hot but now I can't find that reference.

Also, from other pictures, I noticed that my truck may be missing a couling over the fan. One that protects some of the belts from the top. Do you fellas know if this is an important cooling piece or is it just a safety measure to keep hands out of the belts?

 

[nipper]

[quote= Mine is usually sticking straight up / half way to hot.
:roll: