Overheating

So I will have to take the intake out to get to it? Or can I get to it by just taking the alternator out?

Okay, so I think its the thermostat that is bad. Even though it is brand new I think it fails from time to time. Last night, 2:00 am, I found out that it did not open and caused the SUV to overheat. I limped it to the nearest gas station where I did not have any tools to take the thermostat out, but what I did do what remove the upper hose and tapped the thermostat with a screwdriver and then filled up with water and it opened and ran good. My question now is, what can be making the thermostats to fail? I put a new one in about three or four months ago, once it failed I put another one in on the 4th of July and now it has failed. Any idea why they are failing? Do you suggest any brand or type I should get now? Right now it has a Carquest from Advance Auto Parts.

Yes sir. It boiled over and the top radiator hose was not flowing with coolant. After using the screwdriver, to tap the thermostat with the upper hose removed, it opened and once everything was put back together it ran great and the upper radiator hose was flowing with coolant. I am trying to see what is causing these thermostats to fail? I guess I will swing by the fire dealership and buy an OEM part to replace the aftermarket one that is in there.

So now I am wondering if the sending unit is good and the thermostat was delayed in opening. Maybe it was getting hot and before it boiled over the thermostat opened. I guess I will know once I buy a new one. I will keep you posted as to if this fixes the problem.

Replaced with Ford thermostat and it overheated, boiled over. Looked for sensor but cannot find it. Looked on the driver side in the intake manifold as you suggested but there is not one in there. There is a sensor of some type on the front of the engine towards the right on the front. Also, for the time being to get me home, I took the thermostat out and drove home. It did not overheat at all then. I know I do not need to drive too much like that, so do you happen to know of another location the sensor is? Could the one in the front of the engine be the correct one?

I found another a video showing where the sensor is. So thank you for that even though now you do not think that is the problem since it is boiling over.

About four or five months ago I replaced the intake manifold gaskets, water pump, thermostat and I also flushed the cooling system as well.

I was having a problem with not getting any heat in the SUV. I was told it could be a bad heater core or air getting in the coolant system causing air pockets. I saw that my intake manifold was leaking coolant so I knew the gaskets needed to be replaced. After I replaced all of that the SUV started to overheat. I then replaced the fan clutch and thermostat. It still was over heating. I then replaced the thermostat again thinking I just got a bad one. It ran good for about a day or two and then over heated again. Just the other day I put a new thermostat from ford in there and it still over heated. I removed the thermostat and the truck does not overheat now.

So new intake manifold gaskets, new thermostats (only lasting for about two days each before failing), new water pump, new fan clutch. But it still overheats.

Could it be a stopped up heater core? A stopped up radiator? If either of them were stopped up would removing the thermostat allow the SUV to run cool?

Also, let me say when it overheats it does boil over and the top radiator hose is empty. Now that I have removed the thermostat the upper hose stays filled with coolant and the truck does not overheat.

I know there has to be a problem but I just do not know what to do next.

I replaced my water pump with one from Advance Auto Parts, part number T4203. I compared the new to the old and visually everything looked the same as far as impeller and size and bolt pattern. Is there anyway to test it?

I changed the cap around the same time too. I know this is so crazy to me and it is really becoming a headache, but I have to figure it out so I can put another thermostat in there and it run right. To me it just seems like the thermostats are working for about a day or two and then they stop working or start working off and on. For me to go through three or four over this time frame is just crazy.

So to make sure we are on the same page. I need to flush the system to ensure I have good flow. I can also bypass the heater core and then run the engine with thermostat in to see if it overheats. If I bypass the heater core and all works well then I know I need to replace the heater core, but if it still over heats then the heater core is not the problem, correct?

Do you by chance know the heater hose size so I can buy a coupler to bypass the heater core?

Okay, I will try it and let you know what happens.

Sorry it took so long to get back, but been super busy. So the latest is I bypassed the heater cores and installed a new thermostat. It seems not to overheat but now it seems to have a very small stutter when hitting the gas. I was thinking maybe new plugs would fix the problem but haven't tried it. But what caught my eye during the test drive is that when I got up to around 60 mph the service engine light started to flash. What does that mean?