Howdy folks. I know this has probably been asked 4000 times and is probably an annoyance by now, but I've got a 91 ranger with the 2.3 and it doesn't put out too much heat. I've blocked off the rad with cardboard and it will heat up to about 195-200 but the heat doesn't get too great. I'm thinking just replace the heater core, but is there anything else I should check before I do so? How hard is it to replace the heater core?

 

Handyman43358, i have a 1994 2.3 ranger. Very similar to yours. Heater core a snap to replace. 1. squeeze the sides of the glove box door, let it swing down. 2. remove inlet & outlet heater hoses going into the heater core, from under the hood at the firewall. 3. remove 4 screws from the bottom half of the heater plenum chamber, and slide the bottom cover half off. 4. grasp heater core and pull towards you on bottom half, and down. 5. heater core is out, and installation of new core, is just backwards of what you just did.
These 2.3 engines run extremely cool to begin with. The factory water temperature gage is worthless scrap on MOST rangers. Guys are installing aftermarket mechanical or electrical guages to get a REAL operating temperature.If your cooling system is clean, water pump, thermostat, hoses, and guage sender are o.k., then your heater core could be plugged. Have you checked the threads for the blend door fix yet? Rangers are notorious for braking the drive pin off on your flapper door actuator, and cold air blend results.Even though you hear and see the link move, the flapper door can still be screwed up.If you are getting good water flow, then check the blend door fix. i just went through ALL of this on my ranger, Agryphon was a goldmine of help. as well as others. Someone will surely help you out, these guys are GREAT! also check your radiator cap, a good seal is critical to good pressure and temperature production. i have found that a few minutes on the road under load and speed produces more heat output, than 45 minutes at idle!

 

I figured that was probably the problem. The blend door is fine that was the first thing I checked. I've heard it was very simple to replace. Oh and by the way.... the amount of information on this site is unbelieveable. I have been helped and returned the favor to so many people on here.

 

I would verify that there is sufficient coolant flow through the heater core and proper blend door operation first. You can verify sufficient coolant flow by fully warming the engine, placing the temp slider on max, and the fan on high. With cold ambient temperatures there should be a noticeable temperature difference between the inlet and outlet hoses on the heater core. Old Rangers are different than the newer ones concerning the blend door (new uses a vacuum controlled system, old uses cables). I'll assume that the fan speed is sufficient and that the fan speed switch operates correctly.

 

have you even made sure the thermostat is good first?

 

The heater in my 03 2.3 puts out alot of heat. My neighbor's 97 2.3 is the same way. Try flushing out the heater core and a new stat.

 

Thanks guys for your help. 390, the thermostat is good. I have an aftermarket gauge and without the cardboard in front of the rad, its running around 185-190. The only reason I have the cardboard in front of the radiator is so that it will warm up to about 195-200, which puts out pretty good heat. I didn't think that a 5 or 10 degree difference in engine temp would cause that much of a difference in heat output. I actually thought about swapping out fans since this one doesn't blow very fast, but maybe I'm just used to my 95 f-150. It'll run you out of the cab!

 

Let me tell you about an interesting situation I once had. I had a van that would barely move the air out of the vents. It would push it some, but not like you'd expect. I was actually given this old van, and I was at least the 4th owner.

Anyway, guess what the problem was? Someone had installed a new blower motor and had reversed the polarity of the wires. I would have expected the blower to suck air in instead of blowing it out, but it turns out that a squirrel cage type blower doesn't work that way. It'll still blow air, but just barely. If you're getting a small amount of air, it's worthwhile to check the polarity of the blower.