stuck thermostat?

[mp18d]

Yup, I figured it was a bad thermostat. Till I replaced it. Still wont warm up(according to the Autometer gauge..) it barely clears the 100deg mark. Yet factory gauge reads just like it always has. Heater works. Seems to run ok. Trans gauge is a little on the cool side, but our temps here have been in the teens.
Coolant filter head and rad hoses are warm to touch, not hot.
Center post on aftermarket sending unit seems loose, spins with lite wrench pressure. Not sure how it is "supposed" to be but I'll try replacing it. Hate troubleshooting that way but have no experience with motors that "underheat" Lots with overheaters...
Beats the heck outta me....

 

[drmjf]

First, the factory dash gauge is computer controlled then the engine temp get above 160 degrees it show normal temp. Second the temp sender center should not move at all. Replace it.

 

[all ford]

If you replace it make sure you get the long stem one. If you increase it from the 195 degree that ford put in to 203 degrees you probably will see the fuel milage increase 1-2 miles per gal. I increased mine and got a 2.6 increase. The ps cooling system is very effective. IH says these trucks need the 203, thats what they put in.

 

[iracemine]

try cardboard till you figure it out. at least you'll get some heat in the cab.

 

[BIG JOE]

try cardboard till you figure it out. at least you'll get some heat in the cab.

X2.. and when you do replace the sending unit.. you could use a Push On connector, instead of the Nut & Lug ? (the female part of a crimp connector works just fine)

Joe

 

[mp18d]

I'm stumped

Well, replaced the thermostat w/an Autozone OEM. No change.
Replaced the sending unit. No change.
Put cardboard in the grill. No change.
Kicked it. No change.

Now issued is compounded by 10* temps outside and literally 2' of snow in the driveway. Needed it to pull wifes 08 F350 back into the shop this morning. Trans warmed up during the pull (I got it realllly stuck) but cooled rite back down to almost 0. Autometer water temp gauge never left the peg. Obviously it runs good.

It'll get warm, the heater works but certainly not as well as with the 203* stat. Factory gauge goes to the "normal" range but as we all know that means little, xcept it is at least 160*.

Read TG's old thread about his deal with the factory sending unit when he replaced his waterpump. Mine is almost an exact duplicate of his ordeal xcept with an aftermarket gauge. My coolant filter is rigged the same way, and my temp gauge comes off the filter head. It all worked before and after the pump change for a week. Just not now!
If there wasnt so much else going on it mite be kinda fun to troubleshoot this deal but rite now it'sa PITA! Fortunately the freeway (I-80) is closed for the near future so even if I make it into town I cant go anywhere else; one less distraction!

So it's gonna be left alone for a day or so till I get the driveway (all 3/4 mile of it), the horsebarn and corrals, and the trailers plowed out.

Maybe it'll fix itself while sittin in the shop.


Pissin me off!

 

[RSG]

So let's summarize...
You show no temperature on the gauge and it is cold even when running. (which gauge, OEM or after market?)
This cold engine and cab temperature is worse when stopped than when running down the road.
The engine is pulling good and the tranny temp gauge will move up but then drops back down after you "used it good" towing.

Fixes:
recently changed belts, pulleys and t-stat.
worked fine then this happened.
Now you changed to another t-stat and see no change.
You replaced a sending unit for the aftermarket gauge, no change.
You added cardboard in front of grill but no change.

Thoughts:
the original R&R of belts etc -- was something put together wrong?
the coolant system -- is the coolant clean and is the coolant filter new, and is the water pump really pumping?
Is there air in your system that is starving the heater coil?
The cardboard fix is really puzzling, my grill cover makes a humongous difference in engine warmup time and temperature. This makes me really suspect your sending unit and/or aftermarket gauge. Did you double check connections? Can you swap a gauge?
Is the engine as warm as can be expected and it's your heater core that's plugged???

Just running thru the options??

 

[mp18d]

Well, lets see...

Initially, new pump, belt(properly routed according to the diagram), pullys, coolant filter changed. New coolant.

Seemed ok first couple of drives. Then the trip over the Summit, cold OAT, stopped for traffic for couple hours. Had to turn up the heater more than normal, and aftermarket gauge slowly dropped to near zero. Drove fine and factory gauge shows normal (1/2 way) while aftermarket gauge heated up to near 150. Figured stat stuck open so...

Changed stat to OEM- no difference. still had heat but (subjectively) not as much; needed more heater control. Aftermarket gauge reads less than 150*. Dieselsite stat seems to work ok in boiling water.

New sender for aftermarket gauge. no change

Cardboard cover no change.


Complicating all this is very cold OATs and short slow trips due to weather/workload.

Soooo....has it been underheating ever since the new pump etc went in and I never noticed it due to circumstances?? All was GTG before I started screwing with it. If so why. New pump that much more efficient?
I'm thinking the aftermarket gauge bad. Can one be partially bad; indicate lower than what really exists?
Sender is mounter to the coolant filter head on the unused rightside port. Head is mounted to the radiator support; metal to metal.

Coolant filter is mounted per Dieselsite's instructions (I think..) hose from plastic overflow container to left side filter head, then from the front port of the filter head to the port under the thermostat housing (opposite the factory sender).

At the risk of sounding even more dumb, what is the waterflow direction? Isn't the coolant coming from the overflow container to the filter hot? Or is the coolant going the other way from the block to the filter to the overflow??? And doesnt the stat mount with the long shaft/spring pointing down. Stat mounts into the recess in the block, then o-ring then housing??

I'm gettin a headache.

Thanks all for the help!

Mike

 

[dpantazis]

mike-

if i am reading your post correctly, your coolant filter supply is the bypass port on the pump. that is how most of them are routed. the coolant flows from the pump, through the filter, then into the degass bottle. that is correct.

if your autometer gauge is not reading, i would suspect its within the wiring of the gauge, sending unit or to the gauge. usually its a bad ground issue.

in my experience, changing something in the serpentine belt circuit, like replacing it, or changing the belt, will put more stress on the components than they were experiencing before due to no stretch in the belt and forces of the tensioner.

meaning, that parts that were on the bubble as part of a weak system, get pushed over due to the restoration of the force in the belt.

 

[BIG JOE]

Mike, check yer PM's