Thermostat Swap - 192 vs 203 deg F?

[Kelster]

I guess you have had diesel vehicles beforehand? If you haven't you need to know they really won't warm up very well just sitting idling in the driveway. They will warm up some when you are driving down the road, even more if you are pulling with it.

That's the one thing I do not like about these engines. They run so well in cold weather once you get them started, but they do not keep the windshield defrosted unless it's been running for a long time. A gasser is better at keeping the ice off the windshield.

Thanks Franklin2,
I have a 93 F-350 7.3L IDI which is my plow truck and the heater works really well in that rig. I also have a 92 F-250 which is my daily go-to-town driver which is the rig that's giving me trouble. I also have a 1970's vintage Ford 5000 tractor, but that's for another forum but Yes, I have some experience with diesels and have had some training on working on heavy equipment - some formal schooling but mostly on-the-farm training.

KB

 

[pastorjeep]

Well getting that sweet sticky smell...time for a heater core

 

[Macrobb]

That's the one thing I do not like about these engines. They run so well in cold weather once you get them started, but they do not keep the windshield defrosted unless it's been running for a long time.

I've never had any trouble with my trucks; as long as the cooling system isn't leaking into the cab, and the blower door goes to full hot, it works just fine.
Especially with the AC system working - remember that it's used for drying the air when using the defrost.
In my case, I don't just leave it idling for hours; I let it idle for 30-60 seconds and then start driving(though taking it easy). The extra load warms it up a lot faster; water temps get above 120F within 2-3 miles(from freezing).

A gasser is better at keeping the ice off the windshield.

Yeah, I'll bet... that's where your extra fuel is going. ;P

 

[compressionignitionrules]

I've used the higher temp stat on an EFI inline 6 and it improved my fuel economy in winter bigtime. will make truck run a little hotter and possiibly warm up quicker. but if you are doign a lot of trailer pulling stick with the OEM temp rated Tstat.

how much air flow do you have through your heater vents/defrost? flushing your cooling system might be a good plan if you haven't serviced it in a while. if your operating temps are normal don't mess with your Tstat.

 

[Agnem]

Disconnect both hoses to your heater core and push some water from a garden hose through it. My bet is, your heater core is blocked. The stock thermostat, in a standard cab truck, even with the blend door not working, would put out enough heat to chase you out of the cab in short order.

 

[riotwarrior]

Blend door iirc is mevhanical cable but could be vacuum.

Remove heater hoses hold tie them up high....wont leak out.

Remove or open glove box door..tans stop it from flopping open.....once removed acess the panel w about 6 screws holding cover on heater core...remove it remove core...ensure duct is clear of debris...remove core empty it and then fill and soak in kitchen sink w either CLR or vinegar....let sit quite a while...rinse thoroughly.....this may hell...or it may kill the core if its corroded and you cleaned out whats holding it together..

Re-assemble and test.

JM7.3CW Eh!

 

[pastorjeep]

On my 89 it is a mechanical cable. Mine is frozen in the sheath.

 

[Kelster]

So there's a Happy Ending to this thread...

I changed the water temp sensor and now the gauge works as it should.

I pulled the glovebox and the two modules from behind it as well as the cover off the heater core. I broke a piece off the clip where the temp control attaches to the blend damper, but it appears to work Ok. Had a look inside the blend damper area and found a 10 mm stubby combo wrench that someone had dropped or perhaps slipped off the dash and down the defrost duct. It appears to have been blocking the bend door from closing all the way, so my cab is warmer now

But it still seems to take a long time to warm up, so I think I'm going to re & re the thermostat.

All is well that ends well.

KB