"Over" Heating Problem

[Wanderer-rrorc]

What have you read? The thermostat opens at 192 degrees. So either you have a bad t-stat or a bad gauge.

my radiator was plugged from 25yrs of use...I watched it hit 250 one summer day towing my rockcrawler...used to run 190 and then JUMP to 220...then 230...time to turn on the heater...

new aluminum 3 core...190...210 on some SERIOUS full throttle assults....heck on cooler days...the bottom of the raditor is COLD..seriously...I think she's gonna need a button up cover this winter...

 

[Logroller]

my factory thermostat from international is a 175,, and from my service books this is what they 7.3idi is supposed to have in them ,, so if yall are running that hot sounds like you need a factory international thermostat instead of those junk auto parts store crap most ppl buy ...

 

[MR.T]

The Ford manual for my truck says it begins to open at ~192 F, which it does. Full open was over 200 when I tested it on the stove with a thermometer. Works good, been that way for 22 years!

Wanderer-rrorc: I put in a new Spectra aluminum radiator, I think it was a five-row. I know what you mean -- Often I can hold my hand on the bottom tank even though the top is > 192.

EDIT: Just checked my International manual (CTS4245G) for the 7.3, and it says it should open at 192 F, full open at 212 F.

 

[papastruck]

I'm with Darrin on this one. That thing gets over the "R", and the fan should be HOWLING. Climbing out of Denver with my foot on the floor, mine turns on 2 or 3 times the second the gauge goes anywhere near halfway, and isn't on for more than 20 or so seconds.

That the heater seemed to help indicates you're pumping water fine. If the fan's working, I had this happen on a little Ranger years ago, and it turned out to be dirt packed up in the radiator fins, which I couldn't see behind the AC condenser. I pulled it, sprayed through it from behind, and it was fine until it plugged up on the inside a year or so later, at which point the heater trick suddenly failed me miserably.

 

[icanfixall]

Our pumps do have a weep hole just like a chevy... They got that idea from us... Do you know what thermostat is in the motor? Only the factory stats will flow enough coolant. Other autoparts stats will fit but really can't flow enough coolant. Get a mechanical gauge and read whats really going on... Sounds to me like the fan clutch is shot. Use a mirror and look at the front spring thermostat. If there is oily dirt around it then its shot. Replace it with a MS Tech clutch... They are modified to lock up at 220 degrees where the oem units sometimes lock up around 240 degrees....

 

[87crewdually]

ICANFIXALL: Do you think you can throw up a link for "MS Tech clutch"? I can't find it and I'm interested in it.

 

[MIDNIGHT RIDER]

First, some backstory. My temp gauge always runs between the O and R of NORMAL. Sometimes not even getting over the N. I drove out to Ann Arbor today to pick up some groceries at Meijers. Everything worked fine. Got in and started heading to Dexter to pick up Heather looked down and my temp is running between the M and A. Weird, maybe the T-stat hasn't opened up yet. So I keep driving. Get to a stop sign. Sit for 20 seconds or so to let some of the traffic clear. Get back on the gas to go and the needle shoots up to past L and heading for THE LINE! I turn the heat on hot and ful blast fan and as I keep moving it drops back down to between M and A. Goes on like this all the way to Dexter (10 miles) and all the way home (25 miles). Just as I pulled into the driveway, strange, needle goes back down to between N and O. I thought the motor was making more noise while the gauge read hot but it could have been all in my head. Other than that, didn't notice any difference. If it wasn't for the gauge reading hot I'da never known.

My first instinct is water pump. Maybe while idling it's not moving enough coolant to keep the temp in check but when up to speed it's using the extra air flow and rpm's to keep things almost in check. I checked and all the belts were still there. Everything's too wet (1.5 inches of rain today) to see if there was coolant leaking out of it. Do Ford water pumps have a weep hole like Chevy's do?

Any other ideas?

Before you go into a panic, I also read that you saw the oil-pressure gauge higher than it had normally been running.

How about the fuel-tank gauge; did you pay any attention to what it was doing ??

Since you state that the engine did not seem over-heated, nor was there any evidence of it, I kinda suspect that you just experienced a scenario with the Ford factory gauges that occurs occassionally.

I am not certain for your model; but, on my 1985, the factory gauges are somewhat less than 12-volt, therefore there is a voltage reducer gizmo located behind the instrument panel.

This gizmo will sometimes go haywire for a short while and cause the gauges to show higher readings than actual.

That may not be your case, but I would not rule it out.

 

[MIDNIGHT RIDER]

For what it's worth, on my truck, when the needle is on the high side of the "N", the mechanical gauge is steady at 180* .

I can't speak for anything higher, as I have never seen mine above 180*, regardless of load, hill, or outside temperature.

 

[papastruck]

Before you go into a panic, I also read that you saw the oil-pressure gauge higher than it had normally been running.

How about the fuel-tank gauge; did you pay any attention to what it was doing ??

Since you state that the engine did not seem over-heated, nor was there any evidence of it, I kinda suspect that you just experienced a scenario with the Ford factory gauges that occurs occassionally.

I am not certain for your model; but, on my 1985, the factory gauges are somewhat less than 12-volt, therefore there is a voltage reducer gizmo located behind the instrument panel.

This gizmo will sometimes go haywire for a short while and cause the gauges to show higher readings than actual.

That may not be your case, but I would not rule it out.

Good catch - missed that one. Yeah, next time the temperature spikes, check and see that you didn't just get another quarter-tank of fuel. And if you replace that voltage regulator on the back of the instrument cluster, try to get one from Ford. The auto parts store ones were pretty inconsistent iirc.

 

[sootman73]

yea i was thinking it was just the ford gauge that was messin with ya. mine was doing that for a week. after the second time i didn't worry about it. it was moving so much that there was no way there could be a temp change that fast in the engine.

and to clean out a radiator the GM guys take the radiator out and spray scrubbing bubbles and let sit (do it a few times). really cleans the dirt out of them which makes a huge difference in its cooling ability.

 

[icanfixall]

MSTECH phone number is 1800-832-8844 and they are located in Lebanon New York. They have a web site but its down at this time. I tried to copy and post it but it wouldn't work.... I have used three of them. They are the best clutch you can buy. Much better than an aftermarket clutch. What they do is take a new Ford clutch and modify the thermostaic spring in front. They really do work better than stock. When they lock up the sound of air sucking thru the ratiator is loud and impressive. When I pull a grade like we have here in So. Ca. I watch the gauge start going up. Then the fan comes on and the temp goes down as I'm continueing to climb the grade.... Now thats working well....

 

[Agnem]

Damon beat me too it. I read through the first page and I'm goin... Wrong... wrong... wrong... your ALL Wrong!

Buddy, all you needed to do when you were sitting at that light and your gauge started to shoot up, was rap your knuckles on the plastic over your instrument panel. I guarantee what you experienced was a sticking IVR. It would have dropped right back down to normal, and you'd be fine. The FIRST thing I did when I opened this thread was check your sig, and when I saw you had an 86' I knew it was the IVR before I even started reading it, I'm that sure that is what your problem is. Go to Ford and get a new Instrument Voltage Regulator. It attaches to the back of your cluster, and it is essentially a turn signal flasher that takes your 12 volts and applies it to the gauges with about a 50% duty cycle. Mine stick in the on position all the time, and like Damon said your fuel and oil will go up also, but the temp is the most sensitive and will be the one that makes you ignore the other two.

 

[snicklas]

X3 on what Damon and Mel said. That was my first thought when I started reading this also. We had an 83 F-150 and an 85 E-150 both gassers, but they would do the same thing. You would be driving along, and all the gauges would wander toward the high side. Hit a bump, or just the vibration of the road, and they would wander back to where they belong. It was scary the first couple of times that it did it, but they never really got "to high" to worry. If something was really wrong, the guage would still show it.... like low oil pressure, or high temp..... We didn't know there was a fix until I started reading these forums, and just thought it was "normal Ford gauges"......

 

[Agnem]

This problem is a particular pet peeve of mine, because before the internet was invented I had this problem, and replaced 2 thermostats and gallons of coolant trying to make a problem that never existed go away. That little IVR was sent by the devil himself, and if I could work my will I would round them all up, put them in a giant pile and nuke them!

 

[papastruck]

Man you guys were lucky. I slapped the snot out of that dash and they never went back in line, then for me it was try 2 or 3 new ones before the gauges looked reasonable again.