Hello, I'm new to this forum and am looking for some help with my ranger. I have a 98 2.5 ranger with no A/C. I have no heat. At first i thought it was the heater core but my temp gauge is always burried so i don't believe it is. Starting from the beginning here's what i did. I started by feeling the lines going in and out of the core. Both were warm. I change the thermostat and blew out the heater core and coolant lines with my compressor. Drove it the next day for a while and fount that when i'm going up a hill on the gas for a while the temp gauge will come up a little under half way and then i will start to get heat but once i let off the gas the temp guage goes back down to way underneath C. So then I thought mayb it was my water pump thinking the impeller was bad and i wasn't getting proper flow up to the lines and thermostat. i have the radiator filled with anti-freeze and the resovour filled as well and i tried letting the truck run enough to warm it up and bleed the air out of the lines with the rad cap off but the truck doesn't seem to warm up (temp here late has been around 5-30 degrees lately). So i'm not really sure where to go from here. it has fresh coolant fresh pump and fresh thermostat, and the core seems good because sometimes i do get heat when the truck actually warms up, so im sure its not the blend door either because when i cycle the temp **** i can hear the change between hot and cold. Any help would be much appreciated. thank you

 

The Lima engines(Ford 4cyl) at notorious for running cold.

So what many do is to place something in front of the radiator, cardboard or ??, to block air from getting into the engine bay.

If the new t-stat is working the radiator should not even get warm so don't worry about blocking air flow.

The point of the thermostat is to stay closed until engine coolant gets up to 190degF, about 1/3rd on temp gauge, when t-stat is closed no coolant can circulate thru the radiator.
Once t-stat opens cold coolant comes in from the bottom of the rad and when it gets up to t-stat, t-stat should close again if coolant is below 190degF.
T-stat may run closed on very cold days and just slightly open on cold days.

Point being you shouldn't get wide swing in temp like that, 1/2 down to C, reads like t-stat is opening fully and then not closing when the cold rad coolant comes in.

You can also add "pipe" insulation to heater hoses, just on the long runs, it will help hold in the heat.

I would try blocking the air flow first.

Yes, engine generates the most heat when under load

 

When is the last time the cooling system had a good flush.I had the same issue a few years back.I drained the coolant and removed a heater hose and attached the garden hose to it and flushed the the system till the water ran clear out of the rad.I also put the garden hose in the rad(when cool) and flush it too.Of course buddy that I bought the truck from was bad for putting those rad seal pellets in the rad and I think I blew a pound of "Mud" out of the system.Good way to check your water pump is to run engine and when up to temp squeeze the upper hose,you should feel the flow if you don,t feel very much or none then the pump is douched.Try a good back flush and good luck with your heat

 

Try pulling off one of the heater hoses and filling it up there (highest point in the system). I have the prestone flush n fill kit installed on mine so I just unscrew the cap and fill at that point.