Is this a thermostat issue?

[GrumpAzz]

I drive a 2000 Ford Ranger 4x4 with the 3.0 (3.slOw)

It'll blow warmish air until winter really hits. I can watch the temp gauge rise to pretty much normal, then plummet down to where it's not blowing warm anymore. In the dead of winter, it can't get warm enough for the heat to work...

I've already ran into an issue with this pickup when changing a wheel bearing. Apparently, this truck was built late in the year and some of the parts are from the 01 Ranger? Sound lame but that's what they told me...

Over the last two winters, we replaced the radiator (small crack), flushed the heater core, and replaced a vacuum switch that's on the coolant lines (opens and closes to either hold or recirculate coolant, don't know what it was called). At this point, I'm convinced it's a thermostat issue. It works so they haven't suggested changing it, but it seems to cycle too soon and too often. Is there a possibility someone put the wrong sized thermostat in this sumbitch?

Like I said... over the past two winters. I don't wanna go another winter without heat in the truck. I forget in the summertime. I don't usually even remember... I'm reminded.

Crappy video. Dirt road driving.
View attachment Snapchat-361861426.mp4
You see it's warm and then it drops. It does this nonstop and only stays warm for a minute or less. Annoying as hell..

 

[Zen_seeker]

My sister had a metallic green one, Kermit. I don’t recall her having issues with heat and if she did I’d hear about it first. I think hers was from the 90’s as she had a VW Bug and later the Golf/Rabbit/Jetta or whatever they called that car in the end.

It sounds like your thermostat is opening early to recirculate the fluid. Lower temp than what it should be or it’s worn/damaged. Maybe stuck open?

Did you see the thermostat they put in? They usually have a temp number stamped in the middle. See if you can find a repair guide at a store to flip through. We have them at Canadian Tire stores.

I imagine it’s inside/behind the water pump. So two big bolts and a belt will need to be removed. Put down a bucket or cloth as some leaking will occur. Not a hard job. Less than an hour in the old days. Not sure if you have shrouds or crap in the way.

Good luck.

 

[OLDCRO]

I would change the thermostat they do fail. I have seen them installed upside down.