low temp / no heat

have a problem with heat. temp guage below normal 150 degrees or less.
new thermostat, new heater core, and hoses. new coolant.
can block off rad and still will not heat up. need help before i freeze and can't type no more. thankkkksssss. can contact at swetherton@hotmail.com :screwy:

We are having the same problem here. We are at a loss. The thermostat has been replaced twice, ect sensor (pcm)has been replaced, still stays in open loop, ect is around 180°f. It never gets hotter than that. Actual coolant temp is around 160°f at the thermostat housing.

Me too, replaced the heater core, thermostat and backflushed the system and still no heat. Water pump next?

check your fuel pressure if it is over 35psi replace the fuel pressure regulator. mine was 60+psi!

just wondering, what temp is you T-stat set at? Maybe you need to go with a hotter T-stat range. 190 degree range. If thats not it, it may be the water pump crapping out on you (hopefully not though)

Fuel Pressure!!??? Does that have anything to do with it?

My T-stat is 190 degree.

Another possibility is that it might be a faulty blower motor that would keep hot air from being forced into the heater core. That's located on the right side of the engine compartment against the firewall. Just another thought.

Blower motor is fine. There isn't any water getting to the heater core. No blockages that I can find, water flows fine when I hook up the backflush kit. There isn't a control valve on ths year Ranger either. I'm stumped.

It says in the manual, to check to see if the water pump is defective, run the truck at normal operating temp and to squeeze the upper radiator hose. you should feel a pressure surge as the hose is released. other than that, yeah I'm stumped too. Sorry

Yeah you're not the only one either, I've got this problem floating around a couple of other forums too. I haven't gotten a good answer yet. The only thing left to do is replace the pump, maybe the vanes are deteriorating and just haven't got bad enough to affect the engine temp. I've tried sqezzing the hose and I can feel the water flowing through it, I don't know if I would call it a "surge" though.

Have you checked the Heater Control Valve,,,or maybe the vac line has come off not operating the valve,,just a thought.Sorry I didn't see the post above.

An over rich condition will cause the engine to run cooler, ie. not getting heat out of your heater. If the thermostat is good it will regulate the temperture no matter what. The coolant will be forced to stay in the block until it reaches 192f (oem) then it will open allowing cold coolant to enter from the radiator. The heater inlet runs off the engine side so I would check the themostat and then check fuel pressure. Is your check engine light on?

No the check engine light is not on. The T-Stat seems to be working OK, I can tell when opens and closes. I haven't checked the coolant temp to see if it's 192F though. Would high fuel pressure cause the coolant not to flow through the heater core? I could understand the coolant not getting hot enough to create heat but not interrupting the flow altogether.

Try removing the outlet hose on the heater core to see if it has coolant flowing through it when running, if not you need to check for blockage in the hose or engine block or possible a bad pump.

Definitely no blockage, I put a hose on both inlet and outlet hoses and ran water through easily both ways. Pulled off both hoses (one at a time) with engine running and no coolant flowing through. I believe the only thing it can be is the water pump. Doesn't make sense because my engine temp is steady in the normal range.

Is it still cold???

Oh yeah, still haven't figured it out.

My truck will not warm up. (ENGINE TEMP or Interior)

We have recently had a very cold wave come through, but it never gets above the "N" in normal. Usually runs around r or m and provides plenty of heat.

So the first thing I do is top off the coolant. (NO HELP< STILL COLD)

Then I change the thermostat...(NO HELP STILL COLD)

I also let it warm up when leaving work....It makes a green puddle in the parking lot. SO I changed the radiator.

Guess what.....NO CHANGE.

I have also installed cardboard to cut off some of the clean air and it has made no change.

What is the deal???

The low engine temp sounds like a faulty T-Stat. If you bought a cheap one (Stant) they can be bad right out of the box. I would try a better one and make sure its rated for 192F or even a higher temp. The green puddle has to be a leak. Also try purging the air out of the cooling system, I've heard that can cause some weird problems too. None these solutions have solved my problem but that doesn't mean it won't help you.

I know for sure my t stat is working. You can watch the temp come up to almost normal operating temp, then drops back down to the N in normal.

Ok let me hit you with some thougths I have had.....

The truck was so warm it would run you out last winter. So there are two options that it has to run cold this winter. There has to be a configuration change or there is a faulty part somewhere.

I have not changed the configuration to my knowledge so that leaves a faulty part.

Now that we are here, what part of the cooling system would make the engine run cooler when broken.....The T-stat. So I replaced it. No change. Still cold.

Here is an idea I conjured up last night.

The fan on my truck has a clutch on it. The fan is designed to pull maximum air flow through the radiator until the engine reaches normal operating temp. When this has been achieved, the clutch allows the fan to slip some causing less air to be pulled through the radiator.

This is something I have not seen posted on here.

FAN CLUTCH!!!!!!!!

I am going to try it this Friday.

Good luck, let us know how it works. Unfortunately for me I don't think that's my problem. That wouldn't stop water from flowing through the heater core. I'm going to rplace the water pump this weekend and see what happens.

So your engine operates are normal temp?????

That is the root of my problem. The interior will not get warm/hot unless the motor is warm.

Mine is not.

have you check the temp. blend door or flapper to see if its opening or not?

I have a small amount of heat, but nothing like it used to be.

The motor is not running as hot as it used to.

New here. Glad to find this forum. I have a 94 Ranger, 3.0 L. No heat at idle. (Even after 30 minutes) Minimal heat while driving. Bought it in April 03 with a new radiator, heater core and thermostat. Both heater hoses get warm. Blower motor is fine. Temp gauge runs in the low range.

The fan clutch idea sounds ok, but I'm leading towards the water pump.

Badfunkn - let us know if the pump solves the problem!

Tedowski, does your model have a heater control valve? Mine doesn't (93 2.3L) so I'm not sure where yours would be. Look close to the fire wall where your core hoses are run, there might be some sort of switch or valve. If the valve doesn't work water won't flow through the core. Have you tried purging the air out of the system yet?

Badfunkn - My truck doesn't have a heater control valve. I did notice a little coolant on the pump though. I made a few calls and found a new pump today for $25, so I figure it's cheap enough to just bolt on a new one. Now I just need to find a heated garage to work on it.

The Fan Clutch Has Nothing To Do With The Heat. What It Does Is Keeps It From Over Heating. And If It Is Bad Your Truck Will Over Heat.

I'm feeling you on the heated garage, we've had a blistering 20 degrees here all week. My garage is too small to bring the whole truck inside and still be able to work.

Has anybody checked the "doors" in the interior vent system ? I see no model years,engine size,etc. with these posts, but if the hot/cold air door is staying in the cold position,you get no heat.

The Fan Clutch Has Nothing To Do With The Heat. What It Does Is Keeps It From Over Heating. And If It Is Bad Your Truck Will Over Heat.

Where I was going with the fan clutch was that is it stuck in the on postion where the fan spins at the same speed all the time. The clutch does not allow it to slip missing a few rotations. Which would in turn constantly pull air through the radiator and make the truck run cooler.

Ok this weekend, my crew chief convinced me that the truck was running plenty warm enough to produce heat.

So we blew out the heater core using the outlet hose.

Lots of rust and nasty coolant ran out.

That fixed it.

I guess the temp gauge is not reading correctly. It is not in the range that it ran last winter.

Who knows???? Does not matter, I HAVE HEAT!!!!!

Yeah, I checked the door. No problem there.

For everyone with this low temp, heat issue. I don't know if this will solve your problem but it can't hurt to share. One summer my truck was running hot and would not blow AC (cool) air when you got up to speed. I found out the AC relay in the power control box was defective. I know your issue is heat but it might be a similair relay. Good luck

are the hoses getting warm?? if they are then the water is obviously circulating, if not then it could be the pump.

I HAVE HEAT!!!! I replaced the waterpump. It's incredible, the impeller was GONE! There was nothing left but a rusty nub. I don't know how it was circulating enough water to keep from overheating, unbelievable.

Glad to here it man.

Heat in your truck is like sex or air, it is no big deal until you are not getting any.............

I got excited to soon. Decided to head out to the store today and the lower radiator hose blew. Yeah, I should have replaced it with everything else but I didn't think it was going bad. I babied it to the Autozone parts store where I spent 45 minutes in the parking lot fixing the damn thing, in 20 degree weather no less, BRRRRRR!! Fortunately no damage (no warps or cracks in the head) and I'm back on the road, wheww!

Badfunkn - Sorry to hear about the hose, but I'm happy to hear that you finally have heat! I'll be changing my water pump as soon as I get a chance. I Installed a Bulldog remote start system today. Now I'm hopefully just one step away from having a heat machine.

Engine not warming up with rad. blocked off. Some warm air inside not much, and it gets cooler air and temp when i slow down. Replaced t stat twice could i of put it in wrong? it only fits one way. It should over heat w/ rad. blocked
What else could control engine temp.?
Any ideas? PLEASE ..........94 Ranger,, 4 Cylinder

Engine not warming up with rad. blocked off. Some warm air inside not much, and it gets cooler air and temp when i slow down. Replaced t stat twice could i of put it in wrong? it only fits one way. It should over heat w/ rad. blocked
What else could control engine temp.?
Any ideas? PLEASE ..........94 Ranger,, 4 Cylinder

Flush out your heater core. It sounds like you had the same issue I had.

Thanks odb93 I'll try it this weekend

Well I flushed out the heater core and after the 3rd time trying I have GOOD HEAT NOW, but temp. gauge still does not show a normal engine temp like it use to. O'well, I think that prob. might be in a diff. forum lol

Well I flushed out the heater core and after the 3rd time trying I have GOOD HEAT NOW, but temp. gauge still does not show a normal engine temp like it use to. O'well, I think that prob. might be in a diff. forum lol

My truck is doing the same thing.

I am chalking it up to the rust that stopped up the heater core. Probably caked on the sending unit preventing it from working correctly.

Make sure you guys directly flush the heater core when you flush. Remove both heater hoses and hook a garden hose right to the heater core outlet. Flush the heater core both ways. When you flush, open the water valve quickly to give the core a quick burst of water pressure. You may want to hook a hose to the side of the core the water is coming out, this avoids a mess. Also, when you take the heater hoses off initially, you may want to cut them off with a razor knife to avoid damaging the heater core. Moving the heater outlets back and forth to remove the hose will break the solder loose that holds the outlet to the core.