Is this the correct symptoms of a stuck thermostat? My truck has always been slow to warm up but I drive like grandpas's grandpa.. How long does it take yours to warm up?
I usually don't drive it much in cold temps (and rarely unloaded) so it gets up to "operating temps" but I am driving today in closer to freezing and unloaded ... . After driving for 20 min at about 45mph it is still only at 145 degrees... just doesn't seem right..

not looking forward to fighting that if so. It could be original bolts by the looks of it.

 

That or the fan clutch is locked up or nearly so.

 

I would say you have an issue.

My truck is at around 200 degrees eot in about 10 mins of light driving in winter. Slightly depends on temps out side and what i am doing. That said, i drive for fuel economy so i too do not have a heavy foot ( nut well adjusted).

I run the 195 * tstat (the step up that riff raff offers) and a bra in the winter, no ebpv. Without the bra, it still gets warm quickly.

Tstat would be where i start. Get an oem one. I like the warmer one for winter alot, mind you, we have 6 months of winter.
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Yes on the stuck thermostat or there is a piece of minute debris stuck in the valve that prevents it from closing fully. All it takes is a hairline opening and the engine won't warm up unless it's working hard. I've had two of those just on my own personal fleet over the years.

 

That is definitely not normal. I had a bad fan clutch that was stuck on just recently but it would still hold 180-190 with a properly working T-stat running down the highway.

I would say try a new Motorcraft t-stat. I've had bad luck with other ones. Consider a billet aluminum housing for it also. A rare example of the OEM part being crap.

 

Yes a stuck thermostat can cause your concern as it did with my 00, same symptoms as your truck

 

I put a duralast t-stat in mine 5 years ago. Never connected the dots that I never had heat again in winter until this year. Figured it must be stuck open and replaced it with motorcraft. I found the duralast one was a "fail safe" unit that sticks open the first time it opens by design. Garbage!

 

Whew mine wasn't quite that bad but definitely the issue. I DID feel like I should have bought a lottery ticket though when the bolts came out clean after what I think was the original thermostat from 24 years.


years ago.

 

Yes sir.

This is what last weekend had in store for me.



3 for 3 snapped off

Prepped for replacement

Job is done.


Not exactly what I had planned for t-stat replacement during coolant flush and conversion over to ELC.

 

got me a nice "purdy" new one


BTW.. YIKES 😳