overheating unless heater is on

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Dec 30, 2009 | 02:13 PM

colbyclay

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overheating unless heater is on

Hi everyone,
I have a 2002, 2.3L DOHC I-4, 120K miles. Starting last week, I noticed that the temperature gauge was running on the hot side. I turned my heater on to see if that would do anything, and the gauge went back to neutral. I turned my heater off and the gauge started climbing again. I played around with the fan speed and it doesnt matter if the heater is on full blast or lowest setting. I was reading some of the other post and it seems that this might be a thermostat issue. I checked O'reilly's and a new Motocraft runs around $190. My questions are: Could there be any other issues that would cause this? Is there more observations that I need to make before coming to a conclusion? What do I need to do to keep my truck running?

Thanks

Dec 30, 2009 | 04:44 PM

Graygeorge

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Price seems high for a thermostat.
If it has an electric fan, check to make sure its running when hot. Should run all the time when AC is on. If not running, check relay.

Dec 30, 2009 | 05:51 PM

Rockledge

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From: Connecticut

I believe on the 2.3L the thermostat and the t-stat housing are integrated, which means you pay more.

You can find a better deal HERE.

Dec 30, 2009 | 06:03 PM

03 Maz B23

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In addition to thermostat I would check water pump, fan clutch and if it hasn't been done recently a cooling system flush and refill.

Dec 30, 2009 | 08:21 PM

colbyclay

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Quote:

Originally Posted by colbyclay

Update: on the way home, I was paying more attention to the sounds my engine was making. I noticed that even with the heater on, the temp gauge was moving up. Then I would hear a sound from the center to center-passenger side of the firewall. It sounded like pebbles rattling in a can. Once the stopped, the temp dropped (less than a second) back to neutral. This happened 4 times. Each time the temp would be right before the red zone, then gravel sound and quick drop back to neutral. Any thoughts? I still need to do a flush since it was very hot today.

Dec 30, 2009 | 08:28 PM

Eric.S

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From: riverside

It sounds like there is air in the system or the radiator is not filled all the way. Try topping it off then bleeding the system.

Dec 31, 2009 | 12:30 AM

f350duallyguy

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This happened to me on a 97 f150,I changed the thermostat,fan clutch and hoses.Turned out to be my radiator was partialy clogged. new radiator and no more problems

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Dec 31, 2009 | 11:17 AM

Graygeorge

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Didn't know the 2.3 had a special thermostat. You could go to a salvage yard and try and find one cheap.

Dec 31, 2009 | 04:29 PM

#10

joejoebo

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Sounds to me like your thermostat is stuck shut. Had the same thing happen in my 2000 Ranger. Replaced the thermo, bled the air out and now its fine. Good luck.

Dec 31, 2009 | 05:22 PM

#11

customstringer

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From: Ohio

I believe the thermostat is a fairly cheap part and you have to drain the radiator to swap it so I wonder if that's worth a try and with the refill you'll hopefully take care of the potential air in the system as well. I'd check your drive belt also. My two cents.

Jan 4, 2010 | 10:43 AM

#12

colbyclay

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Quote:

Originally Posted by customstringer

Maybe I am a little slow. The thermostat that I quoted above looks like this:

http://images.wrenchead.com/smartpag...MOT/RT1157.jpg

It is around $150. Now, I have looked elseware and found this:

Manufacturer Info

It is $20. That is a huge difference! Can I replace the thermostat without replacing the housing? I would much rather pay the $20 than $150.

Thanks

Jan 4, 2010 | 12:16 PM

#13

Graygeorge

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Have you taken the thermostat out and looked at it to see if it is stopped up or something else is wrong with it. It looks like the one on your engine has a temp sending unit on it which cost more.
If it was mine, I would try to find a used one and see if that was the problem, then I would take the old themostat out of the hsg. and see it I could replaced it with a regular themostat.

Jan 4, 2010 | 12:36 PM

#14

colbyclay

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Quote:

Originally Posted by Graygeorge

No I havent taken the thermostat out yet to look at it. I will do that this evening and see if there are any glaring issues.

Jan 4, 2010 | 04:42 PM

#15

03 Maz B23

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The freestanding thermostat is for the old Lima 2.3. The thermostat for your Duratech 16 valve 2.3 is the $150 one in your post. They didn't design the assembly to be able to replace just the stat. Stupid design and a pricey part but alot more profit for them.