Question about Cars & Trucks
Only warm air, not hot air, flows from the heater vents and the hose on the right of the heater core (standing in front of the vehicle looking on the engine) is hot after driving but seems to be empty. So how do I tell if my water pump has gone bad or is it a radiator?
If the water pump was bad, the engine would be over heating. If the engine temp is normal, then the heater core could be clogged or the valve that opens the water flow to the heater core is not opening. You should be able to see if the valve is opening.
Posted on Nov 26, 2013
Testimonial: "My mum had a bad water pump recently (it was in September) on her Caravan and the engine wasn't overheating. I found out it was faulty only because there was absolutely no hot or warm air from the vents. The problem was the impellers soldering cracked and the impeller was free to not move.. There is no valve attached to heater core hoses in the engine compartments on this Caravan although I had a Voyager that had a valve like that. Did you mean any other valve? I was thinking I might remove the heater control and try to pull the cable myself in order to hear the sound of the flopper inside the heating assembly. I am very sorry for my bad english."
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Posted on Jan 02, 2017
The heater in your car depends upon a flow of hot coolant going through the heater core in order to get hot air into the car. If the heater core is partially plugged, it will restrict the flow. If you have a head gasket that is putting exhaust into the cooling system, it will eventually get into the heater core. When this happens there is no coolant in the heater core to make the air warm. If the water pump vanes have corroded away the result will be very poor coolant circulation causing the heater to not blow hot air. If your car is equipped with a heater control valve that is not functioning properly, the coolant flow will be restricted. One or a combination of these factors is likely the culprit in your case.
Since you state the 2 things you ruled out, that leaves only the water pump. Is the car running hot? The thermostat may be sticking as well... but im leaning toward the pump.
Posted on Jan 21, 2009
sounds like you might have an air lock in the system,try "burping" the system by removing the radiator when the car is cold(had not been started for a couple of hours),then start the car and let it run with the defrost only, on full blast until the car reaches normal operating temperature this will allow any air in the system to escape and this will also cause a little coolant to spill out.When you go to refill the coolant do it when the car is cold if you put cold coolant in a hot engine it tends to case problems with seals and gaskets mainly but can also cause problems for the radiator and related parts,I really hope this helps good luck
Posted on Jan 09, 2010
A couple of things to check because as you describe your symptoms you actually have 2 problems
1. No heat from vents.
Sounds like the heater water flow valve cable is kinked disconnected or the valve itself is stuck You will need to follow your heater core water supply lines to find the valve usually to the right of the center console in the ducting area / large plastic housing for heater and AC internal coils. If the valve works then there is a possibility that the heater core water supply lines have been bypassed on the engine side of the firewall with a coupling due to a leaking heater core. And l;astly the heater core could just be clogged. (quite rare!!)
As for the overheating engine after all of the work you have done.. Perform this simple test.
1. remove radiator cap
2. have someone else start the car
3. watch for water coming out of the open radiator cap area DURING start...
4. have person in the car rev engine gently 2 or 3 times. No need to exceed 2000 RPM. If water rapidly flows out of the radiator during engine revs.. you have some major engine issues.
If it passes all of these checks then the only thing left is improper hose connections on the engine side of the firewall and or a hydraulic water lock in the block that should clear itself by starting and stopping the engine many times with the radiator cap off.
Posted on Jan 27, 2010
There is no such solenoid or valve that controls hot water going through the heater core.One hose hot, one cold, points to a plugged heater core. When you say you flushed it, did you flush the core itself? Do you know that the fluid is running through it? There are no valves in the heater core; it is free flow at all times.Also check the head gasket. just because there is no water coming out of the exhaust dos,nt mean the head gasket is ok.How much pressure is in the system?.Are the water hoses very hard when the engine is hot?.......air in the system will stop the heater from working.------------Also try this procedure to clean the block in the heater core.If there is any:---
Put in a cleaner, Prestone, and drive car few hours.Then check if nNo success. Then get cleaner made by Gunk.You can get it from any local auto part store. Drain heater core, leave both heater hoses attached to the heater. Remove other ends of both hoses from the tubes on the thermostat housing and raise these ends above the heater core. Pour Gunk cleaner in one hose and add water until cleaner started to come out other hose. Leave this sit 4 hours and back flush heater core in both directions. Next back-flush block and radiator in both directions. Water should come out of tube on the thermostat housing that has a hose attached to the outlet of the heater core.If not coming then Flush water directly into this tube about 15 to 20 times and you will hear a thud of water coming out.. Back flush block and radiator again and this time water should out the tube previously blocked. But if problem is same and no difference.Then is faulty heater core.Its causing the problem and it needs to be replaced.------------ This should help.Thanks.Helpmech.
Posted on Jan 27, 2011
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