http://www.partsgeek.com/assets/dimage/full/1001878.jpg

 

As another temporary (till I get the motorcraft thermostat, since everyone only had those rubber wrapped ones for my engine, I picked of a thermostat for what was my old engine, a 1985 6.9, 195* thermostat and for kicks and giggles, one of those emergency lock open ones if you overheat.

If I have got another issue, perhaps the lock mechanism will lock it open and just let the engine run cold rather than overheat.

Let the truck warm up, released the radiator vent, some pressure released
But no overflow, coolant was moving through radiator, drove around town at speeds from 35 to 55 with some light and heavy acceleration (looking for exhaust colorations, just some dark on heavy acceleration).

Since I dont have my mechanical fan due to clutch seized, I have a single (for now) electric fan I switch on or off, had the fan running since it was city driving, since I have a bit of a custom bumper, I also get a lot more airflow to my lower radiator.

While registering higher than before, the gauge read in the middle and stayed there, slight increase on heavier acceleration but it kept center normal while driving vs getting warmer with that rubber jacketed thermostat.

 

I haven't done a diesel yet but all the gasses I have done, the spring goes into the engine, not the housing.

 

Drove to work this morning all on the freeway, engine temp guage kept about 1/3 of the way up once warmed up, only in the final 8 or so miles did it jump to half and slightly above, so I turned on my electric fan and slowed to 50 keeping an eye on it. It hovered at and slightly above half the rest of the trip. When I got up to work, while I transfered gear from one vehicle to the other for a minute, I shut down my truck and left the electric fan on. Then Reparked my truck, I popped the hood, vented the radiator cap (virtually no pressure released) and removed the cap, coolant was just fine, in fact, for the time being, no more oil in the radiator.

I know the engine temp guage is not all that reliable, works a bit but I am wanting to know if there is a good guage I can buy that will give me the exact engine temp, where to install, and would there even possibly be a digital display?

 

I got one that was like that from CarQuest; I removed the rubber to make it like the other.
In my case, it works better than it ever used to... It also has the interesting effect of 'cycling' -- it stays shut until it reaches 195, then opens till it drops to like 185, then closes... etc. I've got a digital temp gauge, so I can watch it cycle.
Of course, if I actually put a big load on the engine it will stay open, but unloaded I don't.

 

When I replaced my stat last month on my 93 T the first stat I was sold had the rubber gasket on it also. It looked JUST like the one in my Dads 97 7.3 power Stroke. I went to the local International dealer and he pulled 3 different stats off the shelf. one had the rubber ring gasket. Did not look at the third one because the second one in the biggest box was mine. It has a separate gasket with it as well. Question for you is does yours have the bypass check valve ball between the block and the stat housing? Mine does. and the gasket has 2 bolt holes, A large water passage hole and a small water passage hole (For the bypass). Yes the check valve ball was a surprise to me as well. I have been told "It lets air past a closed stat when filling coolant."

 

My housing is large, uses an irregular shaped gasket rather than the ovalish one, has a bypass hole above as I recall and what looked like a ball assembly as well.

I guess right now the question I have is there a generic or universal coolant temp gauge I can install for my drive home from work tomorrow that I can get for an auto store and where to install the sensor?

One thing I am curious about, it seems the coolant to the heater core is before the thermostat and there for, if I installed a temperature sensor at the output line before the heater core, I could get an accurate reading...

I have to get new tags for my truck, do other repairs, and take a loaded trip up a mountain in a couple weeks and I want my truck to make it and not spoil the kids summer campout by getting towed back.

Thanks for all the help thus far,

Steven C.

 

Any cheap-o aftermarket temp gauge will work, you just have to pick if you want an electrical one or an old school one with the thermo probe. Digital or analog.

As to the where:

 

I'm just on a quick cool down from working in the heat and replenishing fluids so I'm not all there...

While the pic says not too, are you saying that is the correct port to use without disrupting the stock gauges.

 

Yep, the writing is me being facetious. Some feel the temp reading will be 1/100th of a degree cooler back there and use the over temp sensor port instead. If you do use this port you need a 9/16" 8 point socket perferbably on a 1/2 or better drive to remove the plug, they tend to be stubborn when asked to come out after years of being there.

 

What size is the port for the sensor.

 

1/2" NPT






message too short so I had to type more

 

Thank you.

While not related to the cooling side of the, I just picked up 2 new 19gal fuel tank for my truck since mine are rusting out (reason I am running double fuel filters), both tanks are identical, going to be mounted in the bed, tall and narrow aluminum boat fuel tanks.

Not as big as I wanted but for the time being, I wont be changing out filters all the time.

 

Got the gauge installed, seems half way up on the factory gauge is 200, I can see the thermostat working, based on the way the factory gauge was working, I would guess that my higher temps were about 210, will know when I take a trip later tonight.

 

Freeway speeds, 75mph a bit, 5 passengers and 1000lbs in the bed, engine maintained 210*

Didn't reach as hot as other trips where I'm guessing it got upwards of 220*

How hot is too hot for this engine? What is the ideal temperature range?