Overheating Question? | Ford Explorer Forums - Serious Explorations

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Overheating Question?

FLRyan23

Member
Joined
July 11, 2019
Messages
13
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City, State
Houston, TX
Year, Model & Trim Level
2003, Ford Explorer NBX
Hey guys, I have a 2003 XLT NBX, 4.0.

A couple days ago I was driving, heard a ding, looked down and saw a light that came on saying "check gauges" I noticed that the temperature gauge needle was all the way to the H.

When I would let off the gas peddle, it would go lower, when I'd accelerate, it would go to 3/4. I let it cool down in my driveway, then took it around the neighborhood, let it warm up, and it never went more than halfway.

Yesterday, I went to the store, then was waiting in line at the drive thru at Whataburger and noticed that it would creep from 1/2 to 3/4, then cycle back to 1/2, it would do it over and over, while I sat there, in drive idling, then after driving off, it went back down to 1/2.

Today, I had to run a quick errand and pick up some food for my wife, I noticed that when I was sitting, idled in drive, it would go from 1/2 to 3/4 and back, over and over, but when I idled in park, it stayed at 1/2.

I've been trying to find the cause and/or solution by doing google searches, but haven't found any with my exact symptoms.

Is the most likely problem the thermostat? Could it be something else?
 



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First thing, check your coolant level by removing the radiator cap when the engine is COLD, not hot, then add coolant if needed, start car with cap (if you have a rad. cap. some newer cars dont, and I am not familiar with those), bleed air out by allowing engine to reach operating temp with and un- pressurized coolant system. Watch for coolant flowing in radiator when the thermostat opens, you will feel the top rad. hose will be hot, and the fan will be pulling hot air, if the rad. is full of coolant at this time, replace cap and test drive.
 






This screams sticking thermostat to me

IMO
I'd buy a stant and flush the coolant and replace any radiator hose also check your fan
 






Thanks guys, I’ll check it out and replace the thermostat and the coolant. I’m sure it’s time, I’m at 151k on the clock.

I don’t seem to have a radiator cap, I believe it’s just the reservoir.
 






Just a word of caution -- when I replaced my factory stock thermostat at about 125k miles, I did it just for "preventive maintenance". I was having no issue. BUT apparently, loosing the bolts on the plastic intake manifold caused the manifold to crack. I don't know if yours is a metal housing, but mine was plastic -- then I had to replace the intake manifold.
 












Okay, so I went out to the store about an hour ago. Before I left I popped the hood, noticed that the reservoir was a pretty low. I found a bottle of anti-freeze that was about 1/3 full, poured it into the reservoir, drove to the store and back, no overheating whatsoever.

I bought another jug and will fill it tomorrow and see what happens. I ordered a thermostat off rock auto, I’ll probably end up replacing it anyway and will definitely replace all the antifreeze.

Yeah, I noticed the housing was plastic around the thermostat. I’ve noticed a lot of really cheap and stupid pieces on this truck as it starts to fall apart, lol.

Thanks for the replies, I love this forum.
 






This screams sticking thermostat to me

IMO
I'd buy a stant and flush the coolant and replace any radiator hose also check your fan

Stant is junk. Buy the proper MOTORCRAFT RT1167 thermostat from RockAuto or OReilly's.

Also, be sure you have the proper ratio of antifreeze to water (and use distilled water). Less than 50% antifreeze does not provide enough lubrication for the thermostat and calcium in non-distilled tap water can build up and cause it to stick.
 






Stant is junk

Sorry I have never had a problem
Never seen a problem
My stant superstat was the replacement for the motorcraft
And it's made in the USA I always support my country when possible

Thanks for the advice
 






This screams sticking thermostat to me

IMO
I'd buy a stant and flush the coolant and replace any radiator hose also check your fan
Back in the olden days when I was doing auto repair 30 some years i came across a overheating problem. Replaced the thermostat flush the system but still overheating. Removed upper and lower hoses and found the lower house had collapsed inside but looked perfect on the outside.
 






Back in the olden days when I was doing auto repair 30 some years i came across a overheating problem. Replaced the thermostat flush the system but still overheating. Removed upper and lower hoses and found the lower house had collapsed inside but looked perfect on the outside.
Wow I'd like to see that
 












Agree TechGuru. When looking at Molded hoses back then where the ends were cut you would see cord showing. They would separate there. Did not happen that often but you would chase your tail trying to find the issue. Don't get me started on those darn springs they installed. They would rust and work their way into the radiator and or pump.
 






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