"Over" Heating Problem

[zacky6661]

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.

where can i find the IVR? i have these same problems on my 84, ill be drivin along then watch me magically gain 1/4 of a tank fuel and appear to start running hot so my assumption would be this.

 

[snicklas]

The IVR is a small silver box that is bolted to the back of the instrument cluster itself. To get to it, you have to remove the gauge cluster from the dash. I am not sure where to get the replacement. I dont know if a parts store can get one, or if it is dealer only....

 

[zacky6661]

The IVR is a small silver box that is bolted to the back of the instrument cluster itself. To get to it, you have to remove the gauge cluster from the dash. I am not sure where to get the replacement. I dont know if a parts store can get one, or if it is dealer only....

i just went and quoted one from the stealership, they want almost 100 f***ing dollars for one havent checked napa or o'reilly yet..

 

[papastruck]

i just went and quoted one from the stealership, they want almost 100 f***ing dollars for one havent checked napa or o'reilly yet..

You can find them online for less, but I never got an auto parts store one to work right. This was back in the 90's, so maybe they've cracked the code since then

 

[MIDNIGHT RIDER]

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!

I hadn't had my truck a year when it did the gauges-gone-crazy business.

I can recall it like it was yesterday.

It was prime cruising time on a Saturday night in Columbia, KY, a little one light town with a courthouse square where all the main roads intersect, and a very steep hill.

I was snaking my way through the wheel-spinning teenagers with a loaded gooseneck cattle-trailer.

About half-way up the hill, in bumper-to-bumper traffic, I saw that the temperature gauge was all the way over.

I about went into a panic !!!

Stopping on that hill with a load --- especially livestock --- was out of the question.

I turned off everything I could spare and feared the worst, until I topped the hill and found a place to get over.

No big clouds of steam; no nauseating smell of hot anti-freeze; no hoses burst; no side split out of the radiator; no missing belts; everything seemed fine.

I got back in the cab and checked the gauge again; it was then that I noticed the oil-pressure and fuel-gauge were also all the way over; not just somewhat high, but as far as the needles could travel.

I had no idea what to do, so I rapped the clear plastic in front of the speedometer; and, lo and behold, the gauges settled to normal.

Since that night over twenty years ago, it did this about once every six months for a couple years, just often enough to give a momentary scare each time.

Funny thing is, without me replacing anything, after those few episodes, it hasn't done it again in years.

 

[gatorman21218]

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 ...

My thermostat is from FORD LINCOLN MERCURY OF GAINESVILLE in gainesville Florida.

 

[TBigLug]

I'll have to look into this IVR thing. My fuel gauge never moves but it still could be. Is there a way to test it? My oil pressure onlyjumps up maybe an eight of an inch. Not much, just a little higher than normal. I'll give you an example of what the gauge is doing. Yesterday I'm driving to work, 60 mph, flat road, steady throttle, empty truck. Cruising along, gauge starts out at far left, raises to O at normal rate, will wander up to L then drop back down to O where it will stayfor a couple minutes, then wanders back up to A:L then drops back down to M and stays there until it wanders back up to A then back down. The cyle it's going through isn't sharp movements like I would expect from an electrical short but a gradual rise like a regular warm up cycle. I was watching the Oil Pressure gauge this time cause I just changed the oil and started running Lucas additives for the first time in this truck, all appeared normal, when driving down the road the gauge read straight up and down and at idle in geardropped to just above 'nil lol. Fuel gauge doesn't work below 1/2 tank anyway (E= half tank). I did do alot of extended idling for about two hours around the farm yesterday looking for 5 cows that were wandering around a 60 acre pasture and it spent most of it's time between O and R so maybe it fixed itself. I dunno, but I definitely want to look into this IVR thing. Could be an intermittant short or such. I may throw a new thermostat in it as well. Cheap(ish) insurance an even if my fan clutch was shot it should still stay cooler going down the road than it does. I appreciate all the input and will keep the group apprised of my progress.

 

[MIDNIGHT RIDER]

I wouldn't mess with the IVR gizmo; from what I read, all you will accomplish is to make it worse.


What I would do is to get a good 270*-sweep mechanical temperature gauge and plumb that in; then you will know the real story.

I prefer Stewart Warner or Sunpro MECHANICAL gauges; none of that plastic Autometer junk for me.

 

[MIDNIGHT RIDER]

Oh, and plumb the mechanical gauge in a different hole from the factory one, leaving it intact, so that you can compare values.

 

[TBigLug]

Looks like it's off to the gauge shop once I save up some pennies.

 

[TBigLug]

Well, like my dad always said, you should trust your first instinct. I drove to Jackson yesterday (30 miles) to hit TSC for Dumor Equine Senior Feed and when I walked back out to the truck, what did I see? A puddle of coolant underneath my truck! Nice! Take a look under the hood and above the WP is dry as a bone but the front of the motor under the WP, soaked in coolant. No split hoses, no coolant anywhere else, just under the WP. Looks like that seals the deal. Had to laugh when I looked up the WP at Autozone and it "recommended" replacing the fan clutch as well. $150! Yeah, I bet that's recommended! Suffice it to say, since I'm employed part time trying to support a full-time family, the fan clutch will NOT be getting replaced anytime soon.

 

[gatorman21218]

I used my old (original?) fan clutch when I did the WP. Just put a few drops of blue loctite on it when you tighten it on good. And remember LEFT HAND THREAD!

 

[MIDNIGHT RIDER]

When you have the fan-clutch out in the open, thoroughly clean it, especially the front face and the coil thermostat thingy with brake-cleaner or carb-cleaner.

You can also re-clock that coil gizmo; there was a recent thread with instructions.

 

[rhkcommander]

You kidding? I always knew to beat my ford

Seriously thats how I get my gauges to move to where they're suppose to be sometimes. Friend with similar trucks' blower motor stopped working ... hit the dash et voila it and the odometer started working. My dash lights don't all work all the time - hitting/bumps help. Loose wiring/junk. I'll be gutting my stuff and putting in custom