2005 Explorer thermostat opening late. Replace it three tiimes.

[Neo]

I have a question my bothering law has a 2005 explorer where the thermostat seems to be opening too late and pushes coolant out of the explosion tank. We have replace the thermostat three times with a new one and the same thing is still happening from a cold start. The thermostat opening temp is 88c/192f I am wandering if anyone has had this problem with their Explorers.

 

[Exproblems]

I have a question my bothering law has a 2005 explorer where the thermostat seems to be opening too late and pushes coolant out of the explosion tank. We have replace the thermostat three times with a new one and the same thing is still happening from a cold start. The thermostat opening temp is 88c/192f I am wandering if anyone has had this problem with their Explorers.

No on having that same problem and if you have replaced the t-stat 3 times and get the same results, I would look to another source as to the problem. Have the system checked for a "blockage". BTW, did you install or seat the new t-stats properly into it's housing? The t-stat should be placed in it's housing with the "open mouth" part of the top of the t-stat facing the mouth of the top radiator hose. This ensures proper, unrestricted flow of coolant thru the t-stat and into the top radiator hose.

 

[Number4]

If you aren't getting air out of the system, then the stat may not be in any fluid. So until it heats up via ambient temperature, or by conducting heat, it won't open.

 

[360cid]

This may seem like a stupid response, but are you also checking the t-stat before you actually install it? By placing it in a pot of boiling water with some type of thermometer to check the actual temp opening of the t-stat?

 

[martin_95037]

This may seem like a stupid response, but are you also checking the t-stat before you actually install it? By placing it in a pot of boiling water with some type of thermometer to check the actual temp opening of the t-stat?

Oh I did not think about that and am doing that next time.

 

[fordysenior]

I've never had a vehicle so difficult to get coolant into as this Explorer has been. It showed full, but didn't take enough coolant. Finally,, when it did open up, it took a lot. The manual says to turn on the heat to maximum heat when filling it. Apparently, it had a big air pocket in it.

 

[Number4]

Buy something like this:
https://www.amazon.com/dp/B00804HWOU/?tag=serious-20

Or make your own. Also, use this tool to empty the system.

 

[plasticseng]

The 4.0's will trap air below the thermostat and the thermstat won't open. Make sure that you have water touching the thermostat when it is installed. With the thermostat out, pour coolant directly into the thermostat housing until it is spilling over. Install the thermostat and top hose, and finish filling. I always hook up the scanner and monitor temperature after starting and have never had a problem using this technique.

 

[mountaineer2004]

^^^ Great advice!

 

[martin_95037]

The 4.0's will trap air below the thermostat and the thermstat won't open. Make sure that you have water touching the thermostat when it is installed. With the thermostat out, pour coolant directly into the thermostat housing until it is spilling over. Install the thermostat and top hose, and finish filling. I always hook up the scanner and monitor temperature after starting and have never had a problem using this technique.

fill the 2 coolant bores with some coolant as you are replacing the intake manifold. Also when I was doing the final prep for my gaskets I put a vacuum over a coolant passage and it sucked some coolant out.

 

[plasticseng]

fill the 2 coolant bores with some coolant as you are replacing the intake manifold. Also when I was doing the final prep for my gaskets I put a vacuum over a coolant passage and it sucked some coolant out.

Are you talking about the 4.6? The 4.0 doesn't have any water in the intake manifold.

I'm not sure which engine the original poster has.