94 Ford Ranger 2.3L. My engine will not get warm and I also have no hot air. I have replaced the thermostat, flushed radiator and heater core (clean and clear). Still not heating up and no hot air. Hoses are only warm and water is warm after 1 hr of driving

I put a piece of cardboard in front of radiator. temp guage moved 1/8 and warm air blows

 

Sounds like you bought a faulty thermostat.

 

I think I would look into a faulty themostatic fan clutch. Might be hanging tight and drawing to much air through radiator and cooling too much. Chances of the thermostat being bad and doing the same thing as your old one is very slim. Like less than .005% IMO. Only other thing I can think of would be a blend door problem in heater box, the gauge does not have to move very far on those trucks I've seen many of them not register properly.

 

Yes, Wheelsup is right. Just yesterday I was checking out my fan clutch (for other reasons) and I should've thought of that. Can you spin the fan by hand? With mine, there was resistance, (it would only turn about 1/4 of a turn) so I took the fan/clutch assembly off. Holding the big nut on the clutch by hand, I then spun the fan several times and it loosened up and spun freely. Haynes manual says this is normal since the silicone fluid inside needs to be evenly distributed. You can save a lot of work and bypass all that if you justrun the engine for a minute,then after shutting the engine off, immediately try to turn the fan by hand. It should turn freely. If your fan is locked and engaged all the time, it will keep your engine from warming up. I didn't have the special tools to get the fan off, but I used a longopen-end wrench (1-1/16 inch as I recall) and just hit the end with a hammer to break the nut loose. It shouldn't be on all that tight.

However, I'd guess the most common failure is the fluid leaking out, and the fan clutch would never engagecausing the engineto overheat. Anything is possible though.

 

The fan clutch on the Ranger 4 cyl bolts on to water pump hub thru 4 10mm bolts, It does not have the threaded hub like many others.

 

I have checked the blend door. its working fine, and the fan spins freely, heater core is clean, new thermostat. I am at my wits end here trying to figure out the problem. I just got this truck 2 weeks ago. I wondered why i got such a good deal. someone suggested a bad water pump, but i would think a bad pump would cause the engine to run hot. someone please help!!

 

changed heater core today still no heat. changing water pump tomorrow. I get some heat but only when the engine is rev'ed

 

Spring for a new fan clutch while it is off. Water pump is easy on that truck only three bolts, just be areful not to crack your timing cover when removing..

 

Problem Fixed FINALLY!!! the waterpump was the culprit. I would think and bad waterpump would make it run hot

 

thx for posting the solution of your problem. I watched this post very closely, just to learn and understand how things work and work out... I'm definitely a rookie concerning mechanical issues but I'm also willing to learn from all the discussions here, and it works. Everybody should follow your example and tell everybody the final fix.
Many more miles for you in your now warm vehicle...