`93 ranger 2.3l 5 speed

I changed the thermostat today the gauge on my dash showed the engine temp at just below the normal i figured the thermostat was stuck open. when i ran it today for about an hour in the drive way at idle the gauge didn't even come to the normal line. lower than it was before it is a 195° STANT thermostat i checked it in a pan of boiling water and it opened and closed ok and at the listed temp. now i am thinking it is the temp sending unit where is it located and how would i go about testing it? or is there something else that would cause the gauge to sit so low? the heater pumps out lots of heat when the gauge is at its highest temp.

 

Sometimes it just takes a few days of running to work out the temp gauge readings.

 

On that truck, the thermostat is near the rear of the motor on the side, close to the firewall on the driver side. It's kinda buried under the manifold. Not the easiest to get to. I found that removing the plastic inner fenderwell and using a long extension helped a lot. You WILL lose coolant when you remove it, so you might want to drain the coolant down some to prevent a big spill. Keep your dogs and cats away, they will lick up spilled coolant and die.

Also, check the wire that connects to the sensor before you rip it all apart. If you ground that wire with a clip lead, it should peg the needle on the gauge.

One other thing - I also found I had a bad temp gauge in the dash. Tapping on the gauge would allow the needle to move and register correctly. I got a replacement gauge from a junkyard and popped it into the cluster. Real easy...

 

The gauge temp sensor should read about 3K ohms, when the engine is warmed up. If not, the sender is suspect.

Another way to check your gauge out, remove the connction at the temp sender & try grouning it through a 3K ohm resistor & see if it reads mid scale, in the normal range.

A couple more tests for considration.
Let us know what you find.

 

The gauge is little more than a dummy gauge as well, like the oil pressure gauge...in my opinion.

My Ranger (2.3L) just about overheated during the Hurricane Rita evacuations. I knew something was up when the AC churned out hot air to me but no other signs of anything wrong were present. The temp guage was only pointed straight up when this was going on.

Accurate, huh? Not likely.

 

i bought a new temp sensor to replace the factory one i will see if that helps, now the gasket that i installed when i replaced the thermostat is leaking and i need to re-seal it, the replacement thermostat i bought is a STANT is this a good brand or should i pruchase a different brand i am still kind of new at this stuff and i can use all the guidance i can get! thanks

---Sully---

 

Stant is a good brand thermostat, but for my 3.8L & 4.0L I stay with Motorcraft, as both those have the air bleed valve in them, which helps me bleed air out of the system after I've done work on it, or changed the coolant.

I don't know if Motorcraft or Stant has the bleed valve, for the 4 banger or not, if it does, make sure it is oriented in the "up" 12:00 oclock position & the thermostat is turned the right way, with the bridge section toward the outlet housing & if it has a recess step molded into a casting, that the thermostat is seated flat, in the recess, such that it's not tilted, before you install the gasket & outlet cover, otherwise it'll likely leak.

I also thoroughly clean both mating gasket surfaces on my 3.8L, then butter on a THIN layer of Loctite "Ultra Blue RTV" to those mating surfaces, so the gasket is "sandwiched" between a THIN layer RTV.

This way it'll take up any uneveness or defects, of the gaskets two mating surfaces, to seal any potential leaks, without squeezing out enough RTV to impair the thermostats operation, or slough off any RTV that could get circulated into the cooling system.

But the RTV thing is just me being ****, but then again, I've yet to have one leak either & the oldest work I have an example of, is now 25 years old!!!! lol

In truth though, if we've properly seated the thermostat, cleaned & not damaged the gasket, sealing surfaces, or warped the thermostat housing & using a torque wrench, we've torqued the fastners to spec, (120 inch-lbs.), the gasket shouldn't leak & it should seal itself just fine, without the RTV.

Just some more thoughts to ponder.

Let us know what you find on the leak.

 

I put a stant in my 2002 at 50,000 miles when i flushed the cooling system just to make sure a $10 part didnt fail in the middle of nowhere and leave me stranded. I too am **** about using RTV on most gaskets. Also, torquing the housing is very important. If you just crank it down unevenly you can warp it and cause it not to seal. When you pull it off to re-seal it, put it up against a flat surface and make sure it mates right, also you need to buy a new gasket and not reuse the one you already had on there.

 

i replaced the coolant temp sending unit and the engine temp gauge has risen to about 1/8 the way to hot or overheat or however you call it. i have not had time to re-seal the thermostat housing yet been working alot and when i am not working its eather raining or sleeting. hopefully i can use my brother-in-laws garage to fix that soon but untill then i just keep topping off the overflow tank. thanks for all the help ---Sully---