2002 B2300 (Ranger) runs hot
 

Sorry for the long post...

My B2300 runs hot.
Scantool shows 260F. From a cold start it reaches this temperature quickly, but the dash temp gauge shows normal.
Intermittently the gauge will very quickly (almost instantly) go past the red H and it starts running bad. It has this "prevent engine damage" system?

Shut it off, restart it, and it's fine. Sometimes for many miles/days, other times for only a half mile.
So I was thinking the ECM was getting wrong temp readings causing to go into this "protect from overheating" mode. (I thought faulty CHT sensor)

When I open the hood it certainly did not appear to be overheating, especially when I removed the overflow cap and did not get coolant blown out all over the place.
Coolant level was fine. Hoses seemed to be at "normal" temperature.

Apparently the reading I see on the scantool comes from the CHT sensor (Cyl head temp) which does not feed the gauge on the dash. I disconnect it and the scantool shows -40F
Anyway, I thought "the system" was just getting intermittent wrong signals, but yesterday the overflow bottled poured out coolant after I shut it off.

So it seems there IS an overheating problem.
Oh, also...in the morning the heater blows cold until I drive it.

So I thought to replace the thermostat first, but Ford says I have to replace the entire ($300) T-stat housing.
Autozone has no listing for a T-Stat.

Now what????

I found another (deadend) post on another forum with the identical problem. He replaced the T-Stat which did not fix it.

Pleeeze help :-X21

It probably is the thermostat and it is only sold as an assembly with heater element/sensor/ housing as you were told. If antifreeze is original cooling system should be flushed and check out water pump and fan clutch to be sure it is functioning properly. You do have a cylinder head temp sensor that will shutdown engine before total meltdown but you don't want to go there.. If you want more info on this forum do a search with "Duratech 2.3 thermostat". In those posting someone mentioned checking to see if the electric fan in front of radiator was connected. Check out this link for stat pricing.

www.rockauto.com

Should be this stat at Rock Auto for $102.79 Compare to yours to see if looks the same prior to ordering.

More Information for STANT 48672

Thanks Maz,
But that's exactly what this other guy did and still had the same problem.
$102 sounds much better than the dealer price, and if I knew that would fix it I would jumo on it.
I PM'd this other fellow, hope he responds.
Here's his post

Blown head gasket, buy replacement engine or rebuild head.

Ya', thanks alot.
Figured there's always someone like this on ANY forum.

Might try removing the electrical connection at stat , clean it and using a dab of silicone dielectric grease
( sold at auto parts stores) before plugging it back in. The connection powers the heater which opens the stat.Could also check the resistance at heater to see if it's dead. If you flushed the system,replaced coolant and stat that would probably do it. Only other questionables are the radiator and water pump. Is your coolant level in overflow staying at a constant level?

Thanks again.
So it has an "electric thermostat", (how stupid). No wonder the entire thing would need replaced.
I have AllData, I'll see if it has specs. (doubt it).
Coolant level is not consistently the same.
What might that tell you?
Visually the coolant looks ok, not rusted or anything.
I guess an intermittent heater failure could cause this.

That heater and connection to it are critical as that is what controls it's opening.You might want to do a compression check and visual check of plugs to make sure no coolant on them. The coolant level in overflow fluctuates from cold level to a level once engine warmed up. I made a mark on mine (Sharpie permanent marker)when fully warmed up and use that for comparison. On the stat I also read a post where the tabs on stat housing can break and not keep it in place preventing it from functioning properly. Did you check radiator fan/clutch to make sure it is spinning and not freewheeling?

Fan/clutch? Not yet.
You've been a big help and I agree with you that it sounds like the T-Stat or heater problem.
I'll do some more checking and likely order that stat housing.
Thanks.

I'll check the plugs, but it runs fine and no smoke.

Here is a pic of stat and in this case the computer was throwing a code too. On the fan the clutch lets it freewheel when cold and engage when engine is at opeating temp. Other than the stat the most likely candidate would be a plugged radiator or water pump.If you order stat might want to check whether a new gasket is included. If not check with dealer to see if sold separately and in stock. Another thought is to check the cap on the overflow (essentially a radiator cap).

The Ford Ranger 2.3L Electronic Thermostat

Rock Auto also sells the OE Motorcraft stat for a little more.

More Information for MOTORCRAFT RT1157

Maz,
I looked it up by catalogue and it only comes up as a Stant unit. I'd rather pay the extra and get the OEM.
How'd you find that OEM? Unless you are sure that's it?
That link only shows the image anyway.

EDIT:
Never mind, figured it out.
Gonna go ahead and order it.
I'll let you know if it fixes it.
Thanks VERY much for your help.

Spend a few bucks less and you might be happier.

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(just another sarcastic comment, don't worry)