High Temp Reading

[dieselkid84]

I'm back after a time with a bad computer. Here's my problem with Old Blue my 86 F250. I changed my thermostat from a 180f to a 190f and my gauge started to read in the high side of the gauge. I changed the radiator, water pump and cleaned the system still ran in the high side of the gauge. Order a 180f thermostat and changed it, still doing the same thing.The gauge will run in the middle then start to move to the high side of the gauge. Has someone had this problem?

 

[whiteboyslo]

Most will tell you to only run the Motorcraft thermostat, which is 195. Supposedly anything else can have flow issues. And most will tell you that the stock gauge is worthless, though I know on mine that if it's anywhere near midway, I'm getting HOT. That's the benefit of having an aftermarket gauge and the stock as well.

Are you sure you don't have an air pocket? With all that cooling system work, it's possible you just need to burp it.

Mike

 

[snicklas]

Ok, this being an 86, what are the other gauges doing at the same time? I know when the temperature gauge starts to climb, that gets all the attention, but look at all the others when you notice the temperature gauge climb. Do they all seem to run high also?

The 80-86 trucks are the last generation of Ford trucks that have an IVR (Instrument Voltage Regulator). This can “stick” and cause the gauges to read high when nothing is actually wrong. Our 83 F-150 and 85 E-150 both did this. It will freak you out the first few times until you see all the gauges are “wrong”..... I figured it out when I hit a bump and everything went back where it belonged. After that, if the gauges started climbing, I’d give a thump to the top of the dash and they all went back. The Brick and OBS gauges don’t work this way. Not that they can’t be wrong also, but it’s a different issue, not the IVR.

As most would suggest, put aftermarket gauges in, and then you will know what is happening. Or shoot the thermostat housing with a laser thermometer and that should give you an idea of where you are.

 

[MtnHaul]

Mechanical water temp gauge. Even a cheap-o Equus from NAPA should work fine. Just take the time to verify the gauge is accurate by submerging the probe in a pot of boiling water--don't let the probe rest on the bottom of the pot. Water boils at 212 at sea-level, -1 degree for every 500 feet in elevation.

 

[dieselkid84]

Thanks, the second thermostat was a motorcraft still ran high. I quest I'll check the IVR next, I know Old Blue was built 32 years ago and we have own him all this time. All the other gauges are fine, the oil will run a little high at times I quest I'll have to start with new after market gauges soon. Thanks for the help .

 

[IDIBRONCO]

Aftermarket gauges are the best way to go. The factory ones are just glorified idiot lights to make the public feel better.

 

[chris142]

Did you change the sending unit? That's what goes bad on mine every other year. I have also replaced in stock indash gauge as it went wonky once.

 

[dieselkid84]

I did,I even replaced the first one. Though it was bad, I guest I'll change the indash gauge next it could be bad. Thanks,

 

[nostrokes]

Ditch the dash gauges and get a good set of aftermarket ones. You'll spend more time and money trying to get the factory ones to work right then it's worth.

 

[IDIBRONCO]

As long as I had good aftermarket gauges, I'd just leave the factory ones alone. My own personal exception would be if the gauge wasn't working at all. I just HATE "dead" gauges. Maybe it just a little type of OCD, but that's how I am.

 

[jwalterus]

As long as I had good aftermarket gauges, I'd just leave the factory ones alone. My own personal exception would be if the gauge wasn't working at all. I just HATE "dead" gauges. Maybe it just a little type of OCD, but that's how I am.

You'd hate my truck.
Aftermarket fuel level, oil pressure, water temp, and an old-school grayscale GPS unit sitting on the dash in case I need a speedometer (odometer works, but not the speedo needle ).
I drive by the tach 90% of the time, which is the only functional factory gauge.
Check engine and RABS lights on.
Left turn signal doesn't return, just stays on.




You might think I'm lazy for not fixing things, but my dash is garbage. I have a complete donor cab for the parts I need, and I'll be rewiring the entire truck at that time, but I need to get some other things in life situated before I tear my truck apart.

 

[IDIBRONCO]

I do have to admit that the speedometer in my 85 F250 doesn't work either. I have a universal digital one that I use and plan to just install mechanical gauges in front of the factory one so I can't see it.