91 Overheat Problem

[Survivor61]

Explorer is starting to overheat. nice brown water flowing everyplace. Cleaned everything up, flushed the radiator and started her up. Runs fine, stays cool for about 10-15 min then the needle rises steadly to HOT.

Thermostat problem is my first thought. Question tho, I noticed a electric line on top of where the thermostat is. Is the Thermostat electroniclly controlled? Could it be a electric issue? Or is this line just a temp line?

Anyway, thermostat looks fun to get to, so I just wanted to ask the experts here before I start taking things apart.

Thanks,
Steve

91 Explorer 4x4
V6
Manual Trans

 

[1IronMike]

Sounds like the wire you are talking about is the Temp. sensor. I would start with the T stat and a good flushing, then progress on to the water pump and radiator if needed. Riebe" will have your Radiator in stock for less than $200, did mine last year. Hope its not a cracked head.
good luck.

 

[shamaal]

The statement "nice brown water flowing everywhere" implies a leak. Typical place to look are:
1. Hoses
2. The small hole at the bottom of the water pump (weep hole)
3. Radiator
4. Block

If leak is fixed and still overheats, the thermostat's a good place to start. 1ironmike points out, it's not electrically controlled, just a spring and a wax pellet.

Aother possibility is the fan clutch. The typical test consists of spinning the fan by hand when it's cold, then spinning the fan by hand when it's hot - there should be a noticable difference; of course the engine should be off. A more sophisticated test involves removing the fan and clutch, restting the spring so the fan is on all the time ane evaluating the results. The removal tools are loaned from an autostore.


From there it degenerates into a host of freak problems, some of which are still in the middle of troubleshooting. Do a search on overheat to get a feel for what some of the problems are and feel free to ask questions.

 

[Survivor61]

Ok thanks, just was not sure on that electrical line on the thermostat housing, I thought the heat gauge sensor was on the block someplace but guess not. Ok well off to pull out the Thermostat!! Thanks again for the tips.

Steve

 

[BrooklynBay]

When you flushed the cooling system, did you just dump out the old coolant, and replace it with new coolant, or did you use flushing chemicals to loosen up the rust?

 

[BrooklynBay]

Do you have any oil mixed with antifreeze? Here are some links for you to look at:
http://www.explorerforum.com/forums/showthread.php?t=162848
http://www.peakantifreeze.com/images/art_protection_chart.jpg
Dead Link Removed