1996 Ford Explorer temp gauge and temp change rapidly

Tiny
NATHAN GORSUCH
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  • 1996 FORD EXPLORER
Engine Cooling problem
1996 Ford Explorer 6 cyl Four Wheel Drive Automatic

I have changed both sensors for gauge, changed thermostat and flushed everything and burped air from system, and my temp keeps going up and down. Thought maybe just the gauge but hooked up my hand held computer while I drove and it say my temp is jumping rapidly from 220 down to 150. Back and forth!
Monday, January 18th, 2010 AT 9:53 AM

15 Replies

Tiny
JACOBANDNICKOLAS
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The only thing that I can think of is either (and I realize these parts are new) a bad temp sensor, thermostat, or low coolant. Where are you taking the reading from with your scanner?
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Monday, January 18th, 2010 AT 12:00 PM
Tiny
NATHAN GORSUCH
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I am just plugging my hand held in and it tells live data through computer and when watching it and gauge it changes temps as the gauge moves? Since posting my question I have changed thermostats 3 times 3 different brands stayed with oem motocraft stat. The truck only does this while in motion it can sit in place and idle all day long and temp and gauge stay at the normal temp and gauge stays just below half way! (Normal) If the sensors are bad that I bought I would have check engine light on, be over heating or something! I'm lost on this one please help. Thanks
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Wednesday, January 20th, 2010 AT 10:06 AM
Tiny
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Have you flushed the cooling system? I'm questioning the radiator. Also, check the radiator hoses to make sure they are not collapsing.

Let me know what you find.
Joe
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Wednesday, January 20th, 2010 AT 10:38 AM
Tiny
NATHAN GORSUCH
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Hi Joe, Today when the truck started to do what it does I pulled over to watch the hoses while the temp gauge was up and on its way down the upper hose sucked in and calapsed but the truck still cooled down. So I went and bought a new hose and installed and refilled and it does the same thing with the temp but now when I watch the hose it starts to suck but the new hose doesn;t calapse, but does suck in and feels like it wants to sqeeze shut. What does it meen when only upper hose is doing this? At all other times the hose is warm and hard like supposed to be. Any other info would be great!
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Thursday, January 21st, 2010 AT 5:27 PM
Tiny
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I'm surprised it cooled down. Did you try to bleed the system? If you remove the return from the heater core, coolant should come out of the hose. Check that.

Sorry, but this is going to be a process of elimination. Also, I'm starting to question if the radiator is still plugged even though the you flushed it. Did a lot of junk come from the radiator?
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Thursday, January 21st, 2010 AT 7:21 PM
Tiny
NATHAN GORSUCH
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Hi Joe, The system seems to be clean and working? It takes and puts back coolant to and from recovery tank and all still bright green, and ir the heater core was the problem wouldn't My heat not work? I get great heat and it switches to cold when I turn it to cold? Is it possible that I could have air in the system still? What is the proper way to get air out on the 96' 4.0L V6? It doesn;t have bleeder valves like some? I was told to run with cap off, heat on blast and it would bubble air out, then add coolant? The radiator is full and overflow is at proper line when cold. I hope this can spark more ideas? Thanks again Joe
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Thursday, January 21st, 2010 AT 8:09 PM
Tiny
NATHAN GORSUCH
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I'm not sure if I let you know that when the truck is not moving just running I can let it run for an hour and the gauge don;t act up at all, it stays just below half way and the hoses stay hard and seems normal it is only when truck is in motion?
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Thursday, January 21st, 2010 AT 9:28 PM
Tiny
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That is when the waterpump is spinning faster and drawing coolant up and through the radiator. I still feel that something is blocking the radiator. We'll figure it out.

Joe
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Thursday, January 21st, 2010 AT 9:59 PM
Tiny
NATHAN GORSUCH
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Hi Joe, I will check for blockage again! Please let me know if you come up with anything else. Thank You
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Friday, January 22nd, 2010 AT 12:26 AM
Tiny
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Let me know and I will ask around to see if anyone has a different idea.

Joe
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Friday, January 22nd, 2010 AT 7:17 AM
Tiny
NATHAN GORSUCH
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Hi Joe, Still nothing found for blockage? Is it possible for air to be in system?
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Friday, January 22nd, 2010 AT 8:53 AM
Tiny
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Yes it is possible.
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Friday, January 22nd, 2010 AT 9:05 AM
Tiny
NATHAN GORSUCH
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Hi Joe, Can you tell me the best way to get air out of this particular system? Hope you can assist? Thank you
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Friday, January 22nd, 2010 AT 12:02 PM
Tiny
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If there is no bleeder on the t-stat housing, remove the return from the heater core to see if coolant comes out.
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Friday, January 22nd, 2010 AT 1:56 PM
Tiny
NATHAN GORSUCH
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Hi Joe I checked the heater core line like you asked and yeah I have coolant in that hose. And I made sure I checked right one! Please let me know Thank You very much
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Saturday, January 23rd, 2010 AT 9:47 AM

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