Lower radiator hose or core

Feel the heater hoses near the fire wall, should both be near the temperature of the upper radiator hose. If they are, no blockage in the heater core. As long as the engine is getting up to operating temp. You may have a bad temperature actuator on the heater not switching to heat.

Heater core will not do that, ever. it's just a water bypass to get the hot water to the inside. I think you may need to back-flush your radiator. Take upper and lower hoses off the engine. Stick a garden hose in the lower and seal it best you can. Hold the upper hose away from the engine and turn the water on for about 10 minutes or more. You'l see a lot of stuff come out that shouldn't be in there. Maybe even a wrench or 2(kidding). But that's how to back-flush a radiator. Luck toya bro.

When you replace the thermostat there's usually a purge procedure to get the air out of the system. It can vary from manufacturer to manufacturer but typically on older cars like this you just need to run the system with the heater on and the coolnat cap off until all the air is expelled. You'll also need to add more coolant to the fill tank as the air gets displaced.

Hi there.
Well you can either have a problem with either radiator outer {dust/dirt in outer core of radiator or clogged up inside were water goes, or soft hoses,blowen head gasket plus a few others ,but first go to garage to were you blow up your tyres and use the air hose and blow out the radiator core where the air goes in, 2 drain out radiator water and then refill with water at 1 ltr at a time and then check your info car book and find how much water the radiator takes ,if it dosent take all the ltrs then the radiator is blocked inside.
if engine runs rough missing etc then get your Head gasket checked out.
When you say no heat is that with heat on gauge or no heat from heater, as it could be heater blockage same as radiator core. So let me know how you get on.

The first thing I would do is drain all of the fluid from the cooling system (check to see if there is an engine block drain and open that too) and replace it with water. Turn the temperature setting to full hot and run the car. Leave the radiator cap off when you do this since the fluid level will go down as the car warms up. Add more water as necessary. Now does the temperature gauge on the dash reach the middle setting? Any heat coming from inside the car? Listen to the engine do you hear any noise from the belt side? Possibly a bad water pump? Turn the car off and let it cool down for about thirty minutes. Drain the water out of the radiator (you can remove the lower radiator hose if necessary) and engine block. Notice any sludge coming out in the water? Close off all the drain cocks. Now start the car and add water to the radiator and start the process all over again. The car must be running as you add the cold water to a slightly hot engine to keep the engine block from cracking. Let the car run, watch the temperature gauge, keeping filling the radiator, check for heat inside. Any better? Wait for the temperature gauge to hit the middle point between hot and cold (normal running position). Any heat on the inside? Turn the car off and let it cool again for about thirty minutes. If there is no change then let it cool off for about an hour (engine cool to the touch) and drain the system again. Pull off the hoses that go from the engine block to the firewall (heater hoses). Turn on your garden hose and place it over one of those heater hose openings. Do not turn the water on full blast you may have a leak in the car and I don\'t want you to have a flood. How much water comes out from the other hose (be careful it could be hot)? I have even blown air through one of these hoses to get any water out of the heater core. It sounds to me like you may have some sort of blockage in your cooling system. When you pull off the heater hoses take out the thermostat again and put the garden hose in the engine block to get water flowing through the entire system (all drains and hoses are off to allow the most flow). When was the water pump changed on the car? One other thing that is critical is the possibility of a regulator valve inside the car connected to the temperature setting on the dash. Some cars today do not have any way to regulate the water going through the heater core (flows freely) but if your car has one of these valves it could be bad (frozen shut). Once everything is working correctly remember to fill the cooling system with 50% distilled water / 50% anti-freeze solution.

ok in the engine compartment look at the radiator with the engine cold NOT ON" squeeze the hose with your fingers and feel if hose is crunchy or brittle if is possible a block could have happen locations /points at the vacuum heater valve gate on the heater hoses or a clogged up lower heater hose get a water hose and back flush the heater's hoses normal travel of water is from bottom to top so put the water hose to the tophose and flush backward and try to move the heater valve by finger and see if you get flow (mind you with hoses of the radiator DONT CRANK YOUR ENGINE)

I would be thinking radiator or water pump. When the engine is warmed up and the upper hose is hot, feel the lower radiator hose. It should be hot too, just a little cooler than the upper hose. If there is some blockage in the radiator, the lower hose may feel cold or just lukewarm.
Even though the water pump doesn't leak, the impellers may be made of plastic and have considerable wear. That would restrict circulation.
The heater core should not be an issue. Heater cores do not cause overheating even when totally plugged up.

Hello! There isn't a sensor that would disallow heated water to circulate through the heater core...If the temperature gauge rises to normal...And the upper radiator hose is hot along with the lower hose ...I can conclude water is circulating through the block...Question then becomes; Is it circulating through the heater core? And the answer to that is, I don't think so...With the heater control turned on high feel the outlet heater core hose (facing engine it's the one on the left) if it feels cold or not as hot as the inlet then one of two items are at fault...#1...The Plenum assembly, which the heater core sets in has an open vacuum line...#2...The heat control valve cable or the valve itself is not opening...See picture of valve below...It is on the firewall...Let me know if heat is passing through the heater core...If hot water isn't passing through the core and the valve is opening than the core itself is blocked...send a comment...Guru...Saailer

MOTORCRAFT Part # YG229...$20

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

The thermostat is where your lower radiator hose meets the engine block. There are three bolts to remove to get to it, if your engine is a V6

Sounds like you have a clogged heater core. Sometimes heater cores can be flushed, but more times than not, it has to be replaced. If you've replaced the thermostat and your lower radiator hose is always cold, chances are it is the heater core. Hope this helps! Have a great day!