Heat Is Too Cool, Gauge Jumps Around | Ford Explorer Forums - Serious Explorations

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Heat Is Too Cool, Gauge Jumps Around

gregthomas

Member
Joined
February 13, 2009
Messages
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City, State
Irvine, KY
Year, Model & Trim Level
'95 Eddie Bauer
Hi, I'm a newb to this forum and this is my first post. I did search here but I haven't really found an answer to my problem. I have a '95 Eddie Bauer that has a strange problem. The temp gauge goes up and down as I drive. It usually goes from right on the bottom mark of the normal range to half way up, and continues this no matter how long I drive. Sometimes if the temp is below 30 degrees out, it will dip down below the normal range. Also, the temp of the heater goes up and down too, but it doesn't seem to be in sync with the engine temp. I replaced the thermostat, flushed and burped the system but that hasn't helped. One thing I noticed was that the old thermostat I took out was in backwards. At least I think. The pointed end was inside the engine block and the spring end was inside the housing that goes over it. Anyway, I put it in both ways and it made no difference. Which way is it supposed to go and does anyone have any pointers to the temp gauge/heater problem.

Thanks,
Greg
 



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Spring side goes toward the engine, the little bypass hole goes toward the top. I put the thermostat in backwards on my Ranger once, and it wouldn't warm up properly..
 






Thanks dogfriend, the old one I took out was backwards and I put the new one in the same way. When it still had the same problem, I turned it around the other way. It is in correct now then, but I still have the same problem.
 






Thanks dogfriend, the old one I took out was backwards and I put the new one in the same way. When it still had the same problem, I turned it around the other way. It is in correct now then, but I still have the same problem.

More than likely the one wire gauge temp sender is bad. Very common on these year explorers. Change that if you want to get more accurate readings.

Also the OHV is difficult to burp air from. Run it to full warm with the cap partially on. Make sure the heat is on high when you do this (important).
 






More than likely the one wire gauge temp sender is bad. Very common on these year explorers. .

If that were the case his heat wouldn't get warm/cold as the temp gauge moves.

Honestly, it still sounds like a t-stat issue. That's what maintains the engine temp. It IS possible that you got a defective t-stat. It's a cheap part, I would put another one in and make 100% sure it's in there correctly. Also make sure it has the small hole on top.
 






If that were the case his heat wouldn't get warm/cold as the temp gauge moves.

Honestly, it still sounds like a t-stat issue. That's what maintains the engine temp. It IS possible that you got a defective t-stat. It's a cheap part, I would put another one in and make 100% sure it's in there correctly. Also make sure it has the small hole on top.

You are right, preferably a motorcraft one.
 






Ok, I'll try the Motorcraft t-stat. One thing I noticed this morning was that it works good out on the open road, but when I'm idling in town and the fan is on high, it blows cold air. If I put the fan on low, the heat comes back. I wonder if the heater core is clogged up?
 






I wonder if the heater core is clogged up?

I was going to suggest that you might have some blockage in the system. You are not going to be happy about changing the heater core on a 2nd gen Explorer though.
 






I was going to suggest that you might have some blockage in the system. You are not going to be happy about changing the heater core on a 2nd gen Explorer though.


Expensive I guess. Can I flush the heater core without taking it out? Would flushing even help a clogged heater core?
 












The heater works fine now, must've been a big air bubble in it somewhere. Temp gauge still goes up and down, but I can live with that as long as the heater works!
 






Solution to heater problem?

Did you end up flushing to get the heat working or bleed it again?
 






You probably didn't install the thermostat correctly. If it's indeed a Motorcraft thermostat, the hole on the thermostat must be lined up with the gap in the thermostat housing at 12 o'clock.

If it works, live with the fluctuating gauge until it drives you crazy enough to reseat it!
 






Did you end up flushing to get the heat working or bleed it again?

Well I just drove it, and it got better. However, when I took my daughters to school this morning, it was about 20 degrees here and it took about an hour of driving before the air coming out of the heat duct was hot. Most of the hour of driving the air was just warm. Later in the day it warmed up to about 30 degrees outside and the heater worked perfect. Would not lining up the hole cause the heat to only get warm? I don't think I lined it up properly. BTW - this is a new Stant thermostat.
 






my heater blew cold or hardly warm air so I replaced the heater core now it works allmost to good after 20 min its like the tropics and it was such an easy fix on my 91
 






Yep, its much easier to replace the heater core on the 1st gen Explorers and Rangers - but they changed the design of the dash in 95 + and there is no access to the heater core.
 






Ok, I think I've figured out the problem. If I turn the heat control all the way up, it's only warm air. If I turn the knob about a 1/2" from all the way up, in other words turn it from the 3 o'clock position to about the 1 o'clock position, it gets hot! Sound like the blend door is about to break?
 






From what I have read about the blend door problem, the symptoms are that the air either goes full hot or full cold (usually the opposite of what you want depending on whether its summer or winter). I think you lose control of the temp because the blend door gets stuck in one position.
 






i think it sounds like to me that the only reason it blows hot air when its on med and cold air when on high is becouse the air is not moving as fast as if it was on high so i am leaning towards the heater core if the core was working right you would have hot air without the core you basicly just have a fan . i went threw the same thing and a new core took care of it now on my 91 it was so easy a 30 min fix but i hear that it as a royal pain in the ass on the 95 you have to pull out the hole dash and set aside at least 15hrs for the job . what i like to do if im not sure about how somthing comes apart is i go to a u-pull it and do like a dry run open it up and look around if you know what i mean plus you find some cool stuff
 



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i think it sounds like to me that the only reason it blows hot air when its on med and cold air when on high is becouse the air is not moving as fast as if it was on high so i am leaning towards the heater core

Well, I would've agreed with you a couple of weeks ago, but I think there was an air pocket in there somewhere that made it's way out because now it doesn't do that. The problem now doesn't have anything to do with the fan speed, only the temperature control. If I put the temp all the way up on high (3 o'clock) it blows warm air, but if I turn the temp down a little (1 o'clock), which should be cooler, it gets hotter. If I continue to turn it down past this point, it gets colder as normal.
 






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