Hi All, dash temperature gauge starts all the way on cold on a cold start in the morning, then after highway driving the gauge reads on the lower end of the middle portion between cold and hot and doesn’t get any higher than that after driving at 60 for an hour or so. I didn’t replace the temperature gage in the dash panel or the temperature sender on the engine.

I rebuilt the factory AC and got it plumbed up and working and at best the heat coming from the heater is lukewarm. I put a new pro source heater core and new lines and new motorcraft yg133 heater line valve. Before I installed the valve I noticed there was a smallish hole in the open position and thought maybe that needs to be drilled out?

Both heater lines feel hot just below the point where it would be too hot to touch. I replaced the thermostat with a 180 Napa premium. I just ordered a Stant 195 and 180 to try replacing thermostat.

I don’t believe I’m feeling a lot of engine heat driving down the road. I single checked blower door operation a few weeks ago but I should double check to make sure heater core is getting proper door operation.

Is there a way to verify with the actual operating temperature of the engine is so it can be compared to the temperature gage on the dash? I have a temperature scanner. What actual measured temp should engine be running at? I think the engine should run at a proper temperature to minimize engine wear and boil off condensation in the oil.

I’m in Nebraska and it gets cold but not like farther north.

Thanks,
Sam
1972 F250 4x4 360

 

By a cheap infrared temperature gun. You can use it to get an idea of the motor temperature and the temperature of the air coming out of the heater.

 

I'm not certain when Ford went to higher temp. thermostats, tho my '64 Truck Shop manual sez "All Engines - opens at 185° - 192° F. fully open at 210° - 212° F."

If you live in Nebraska, install a 190° or 195°. Trust Me. The heater will work much better than a 180° thermostat. Use a good quality T-stat.

 

Thank you for the tips.

 

Yep. IR gun can be had for 20-30 bucks. And you'll find a ton of things to use it for.

X2 on using a 195 stat.

 

Does the dash lever actually open and close the heater valve?
If your hoses are hot then the new core should be hot. But if the valve doesn't open you'll freeze. And the heat can get to the valve from both hoses.
I'm from cold country myself and the truck heater can easily overheat the cab even on below zero days.
One problem that I encountered was now having enough anti-freeze. The radiator would freeze while I was driving. Frozen radiator equals no coolant flow through the core either.
My solution was a piece of cardboard in front of the radiator to block *most* of the cold airflow.
Figure if it is a static -20°F then the windchill as you drive can easily get to -50°F.
I was driving in Flagstaff's record cold of -40°F the first time my radiator froze.

 

A 50/50 solution of antifreeze & water is good to -34° F. below zero. Water must be mixed with the glycol to achieve extended freeze protection, straight undiluted antifreeze is only good to +20° F. iirc. A 70/30 mix provides maximum freeze protection to -67° F. below zero. Should not have any problems with radiator freeze ups.

 

Once upon a long ago I had a nifty glass coolant mix temperature tester. It looked like a miniature turkey baster. One would just suck up some coolant and look at where the little colored ***** were on the background label
to see what temperature the mix was good for. Sadly it got broken during one of my long distance moves.

 

I've always just stuffed 2 gallons of undiluted antifreeze into the radiator after flushing the system completely with water, in a 16 quart system. Close enough for a simple guy like me, just trying to do a simple job. I've read, don't know how true it is, that even very dilute solutions of coolant will provide freeze protection at least in terms of actually protecting the block from cracking. It may turn to slush, but the block won't be scrap metal. The problem with places like Arid Zone A, people think they can save money by running straight water, and it causes serious internal corrosion very quickly, the scale and rust sediment soon causes restrictions in the cooling jackets. Then the peeps remove the thermostat to try and prevent overheating, which tends to cause internal oil sludge from condensation, acids form in the crankcase that eat main and rod bearings etc.

 

The solution to the straight water corrosion is to use something like Redline, (https://www.redlineoil.com/waterwetter), water-wetter or some water soluble oil.
One other problem that straight water has is that it lacks a lubricant for the water-pump seal and the seal will go out fairly quickly. Redline helps protect the seal.
I've been using the stuff for some 40 years or so and I recommend it.

I run straight water most of the year with the water-wetter. Water has a higher latent heat transfer than anti-freeze solution. I switch back to anti-freeze in the cold days of "winter".
Cold days... LOL
40°F is cold. Anything warmer is almost t-shirt weather. I gave away my down jacket and vest when I moved here years ago. lol

 

"40° F. is cold"

Ah... no. No it ain't!!! LOL. It might seem like it, if you're not used to it. I was stationed on the Big Island in Hawaii for three years, flew home in January to pick up my car in Seattle. It was about 40° there when I stepped off the plane. I didn't care for that too much. Seemed really rude. It got worse, because I had to drive across Washington, Idaho, Montana, etc.

 

Hah! Yep, around here we keep our down jacket in the back just in case the temp goes below 60f! Rude indeed!
Except for the UPS drivers, who I swear are all from Minnesota or Montana. What with wearing their shorts and short sleeve shirts all year round, snow or not.

I know our visitors from parts east and north must laugh at us all the time. What with our narrow personal comfort zones. Comes naturally when you never know if Thanksgiving will be 45 and raining, or 80 and clear!
The good news though, is that anytime someone is in SF on an 80° day, but after 3pm it drops to 45 when the fog rolls in, we're prepared! Extra jackets and sweaters come in real handy.

Paul

 

Oftentimes people will say the coldest they've ever been isn't when it's 0° or something like that (though that is cold) but when it's well north of freezing, and they get wet. That's when the majority of hypothermia cases occur too, pretty sure. Freezing weather and snow isn't fun, but at least it's dry. High winds and rain, not having the right gear or prepared for it can make things real dangerous real quick.

 

A good check is to loosen the radiator cap, tape it on, warm the engine, and check the coolant at the neck with a meat thermometer.
At least you know where the gauge is at that temperature. I found mine happy, about 190, even just touching the normal range.
It is the hottest after coming to a stop getting off the freeway, or idling in place. It warms slowly idling. Drive it.
Voltage in your dash can effect the Temperature Gauge. (See voltage regulator posts.)

My temperature gauge does the same thing as yours. Only goes up to the lower part of the normal range.
A clean block and big radiator stays cool. I only saw it get in the middle once, and that was in summer, Nevada, pulling a trailer up a hill.
I'm running a 195 deg F thermostat, which is recommended, except perhaps for constant towing.
When it gets under 40 deg F, you might put something all the way across the radiator. This avoids making a hot-spot, and stressing the seams.
Coroplast from signs works well (Polypropylene) in really low temps.
You might put fold lines across it, and 'unroll' it as temperatures change. I have room for four 2" strips.
If you put it down low, it will provide more protection from winter road sand, pea gravel, etc.
Around zero, I pretty much covered the whole radiator up.
There are advantages to using an expanded mesh. No hotspots, keeps bugs and rocks out, and mud dries out and falls off.
Take care with rubbing the fins. Don't forget to cover your trans cooler below freezing.

(Former Colorado High-country guy.)

 

If I remember correctly there is a step down transformer on the gauge cluster which drops the voltage to the gauge panel. If it is bad, it sends a lower than normal voltage to the gauges, and the oil pressure, and temperature will read low.

My dear ole Dad, put a whole new cooling system in my Mom’s Volvo, because he didn’t want to hear a smart *** kid telling him it was the gauge transformer. Hers was failing and sending full voltage to the gauges, and they were reading high. My clue was she ran out of gas twice. But she was sure she had a quarter tank. Dad focused on the high water temperature the gauge was showing. So, he bought a radiator from the pull-a-part yard, and had a radiator shop rebuild it with an extra core. He replaced all the hoses, and installed his new radiator. And, it still “overheated”.

I went and bought a new transformer, for $30 at the Volvo Dealer, and installed it in an out twenty minutes.