No heat and not reaching operating temps

[JitterzdaGod]

I have a 99 ranger 2.5L that has no heat... I've replaced the thermostat with a OEM motorcraft one and nothing still no heat.. Read around on the forums saw that maybe it's a water pump issue so I replaced that too and still nothing. Hoses coming in and out of the heater core are both warm so I don't think that's the issue.

Additionally when idling the temp gauge won't move above the "C" line and will blow out ice cold air. When driving or just keeping the RPMs up it will increase a little bit but never going over maybe a quarter of the gauge at most and then as soon as I stop at a light the temp needle drops back down and ice cold airs blows out again.

 

[tomw]

I would remove the thermostat housing and inspect the stat for installation. It must be shoved into the housing so the rubber gasket is seated, and then held firmly square in the housing by bending the legs as necessary. There are flat tabs on the legs that should fit into a groove on the gasket surface that will hold the stat in place in addition to mushing the legs so they run into the inner diameter of the housing.
You should NOT feel any heat in the hose from the thermostat housing to the radiator, or barely any, until the engine is at operating temperature. You can check that before doing the above, and if the hose begins to warm up immediately, OK, a few minutes after startup, odds are the stat is bum or loose in the housing. BTW, don't get a stat made by Bob's Pizza and Tractors as they don't know how to make a good one. Stick with OEM or a known brand, and even inspect them for quality as some have decided profits are all.
As far as the heater hoses, they BOTH should get too hot to keep your hands on them. If one is warm, the other cool, the core is likely blocked. You may be successfull in flushing with a garden hose, but it may be in need of replacement.
If you have a valve in-line in one of the heater hoses, make sure it is opening all the way.
tom

 

[JitterzdaGod]

I would remove the thermostat housing and inspect the stat for installation. It must be shoved into the housing so the rubber gasket is seated, and then held firmly square in the housing by bending the legs as necessary. There are flat tabs on the legs that should fit into a groove on the gasket surface that will hold the stat in place in addition to mushing the legs so they run into the inner diameter of the housing.
You should NOT feel any heat in the hose from the thermostat housing to the radiator, or barely any, until the engine is at operating temperature. You can check that before doing the above, and if the hose begins to warm up immediately, OK, a few minutes after startup, odds are the stat is bum or loose in the housing. BTW, don't get a stat made by Bob's Pizza and Tractors as they don't know how to make a good one. Stick with OEM or a known brand, and even inspect them for quality as some have decided profits are all.
As far as the heater hoses, they BOTH should get too hot to keep your hands on them. If one is warm, the other cool, the core is likely blocked. You may be successfull in flushing with a garden hose, but it may be in need of replacement.
If you have a valve in-line in one of the heater hoses, make sure it is opening all the way.
tom

The heater core hoses are the only thing that get too hot to touch. My top end hose doesn't even get too hot to touch. When I installed the thermostat I did it exactly how you described and I know there's no wiggle room in there. I got an oem ford motorcraft one.

 

[tomw]

Two things are left: Low coolant and plugged heater core.
Low coolant would keep the gauge reading... Umh. If you have the gauge sending unit on the side of the block, then unless the level is WAY low, there should be contact between the gauge and the coolant.
The heater core could have blockage in portions, which would make all the coolant flow through a limited area and make the heat transfer limited. Only with higher rpm would you flow enough coolant to warm the air.
It is also possible that there is blockage of the airflow over the heater core caused by 'stuff' that got down into the plenum at the base of the windshield. You'd get heat as long as the flow was fast enough to keep that smaller area hot.
Have you checked for flow using a garden hose, etc? Does the upper radiator hose ever get hot? What is the ambient temperature? The Lima can be 'air cooled' by the airflow at speed through the engine bay, and actually not even need the radiator in chilly weather. That would explain the cool upper hose. A partially blocked heater core would explain hot heater hoses and lack of heat.
tom

 

[JitterzdaGod]

Two things are left: Low coolant and plugged heater core.
Low coolant would keep the gauge reading... Umh. If you have the gauge sending unit on the side of the block, then unless the level is WAY low, there should be contact between the gauge and the coolant.
The heater core could have blockage in portions, which would make all the coolant flow through a limited area and make the heat transfer limited. Only with higher rpm would you flow enough coolant to warm the air.
It is also possible that there is blockage of the airflow over the heater core caused by 'stuff' that got down into the plenum at the base of the windshield. You'd get heat as long as the flow was fast enough to keep that smaller area hot.
Have you checked for flow using a garden hose, etc? Does the upper radiator hose ever get hot? What is the ambient temperature? The Lima can be 'air cooled' by the airflow at speed through the engine bay, and actually not even need the radiator in chilly weather. That would explain the cool upper hose. A partially blocked heater core would explain hot heater hoses and lack of heat.
tom

Don't think it's low coolant I've had to drain the system and refill it so many times I think I've gotten the hang of topping it all back off lol. I haven't tried flushing the heater core I assumed because the hoses were hot I didn't need too. Would flushing the heater core fix the temp gauge reading real low though? I just feel like that might fix heat but still doesn't explain the car not reaching operating temps.

 

[tomw]

If it is not getting to operating temperature, and you replaced the thermostat AND you fitted the stat into the housing correctly, THEN I'd suspect a bum thermostat out of the box. It does happen.
How can you have HOT heater hoses, (both are supposed to be too hot to lay your fingers on for any length of time, repeat BOTH) AND have a temp gauge reading near "C"?
Well, the gauge could be bad, the sender bad, or you could have poor ground of the sender where it screws into the side of the block.
A summary of what you report:
1)no heat from heater except if rpms are up
2)both hoses hot(real hot?)
3)upper radiator hose never gets warm
4)new stat
5)new water pump
6)coolant full, no bubbles(did you 'work' the high spot where air accumulates to top tank)?
7) gauge never gets above "C"

Is that a close summary?
tom

 

[JitterzdaGod]

If it is not getting to operating temperature, and you replaced the thermostat AND you fitted the stat into the housing correctly, THEN I'd suspect a bum thermostat out of the box. It does happen.
How can you have HOT heater hoses, (both are supposed to be too hot to lay your fingers on for any length of time, repeat BOTH) AND have a temp gauge reading near "C"?
Well, the gauge could be bad, the sender bad, or you could have poor ground of the sender where it screws into the side of the block.
A summary of what you report:
1)no heat from heater except if rpms are up
2)both hoses hot(real hot?)
3)upper radiator hose never gets warm
4)new stat
5)new water pump
6)coolant full, no bubbles(did you 'work' the high spot where air accumulates to top tank)?
7) gauge never gets above "C"

Is that a close summary?
tom

Both hoses are not so hot that you can't lay a finger on it for a few seconds though. I'm gonna back flush the core today and see if that helps.

Coolant is full and I burped it and kept filling for a solid 20 minutes and filled the overflow.

Gauge will read above C only when driving but as soon as I stop it drops right back down to C again.

 

[atikovi]

Sounds like you have air pockets in the system. You need a vacuum tool to properly get it all out.

 

[tomw]

IF:"Gauge will read above C only when driving but as soon as I stop it drops right back down to C again."

then the thermostat is allowing coolant to flow through the radiator when you are moving, cooling it down. The engine will produce MORE heat with higher rpms(driving!), rather than less, but the radiator cooling, via fan or motion, will cool the coolant in the radiator.
If it cools, then the coolant in the radiator MUST be flowing, meaning the thermostat is open to some degree.... unless you can get it to back flow through the radiator somehow. Radiant cooling from the fan or motion blowing air over the block just should not be enough to drop the temperature on the gauge. Sitting still or in motion, the thermostat should raise the temperature of the coolant over a short while. It should show on the gauge. If not, something is wrong.
The heater hoses should be so hot that you can touch them for a second, one, and be uncomfortable. They should be too hot to keep touching for ANY length of time. UN-comfortably hot. If you can handle them for 5-10 seconds, they are not as hot as should be. Again, either the coolant is not flowing(new pump should keep it flowing), or there is not enough(I found I have to bleed air out of heater hoses to get the core full of coolant)coolant in the system. I have burped by depressing the heater hoses, one at a time, to allow any air to rise to a high spot. I have a Prestone flushing tee installed, and can bleed air out of that, so maneuver hoses to get air to rise to the spot of the tee, and then open the tee 'cap', and allow air out. Raising the front end on ramps while trying to bleed air in the other direction also can help.
What is the ambient temperature? U no answer.
tom