Heater does not give out heat all the time

GENERIC INFO: You need to deal with the 2 hoses that lead to the heater core. From COLD. Start the car with the heater turned to max, now go and feel those heater hoses as the car warms up. Heat should pass through one side and then shortly thereafter come through the other side. They don't get hot at the same time if working properly since water enters the heater core and exits to the cooling system.

If they both get hot at the same time it's the heat from the engine slowly going into them indicating that the coolant isn't moving through the heater core. If that's the case you'll need to flush the heater core or replace it unless you have another HVAC control that needs to be tested such as a heater control valve that would restrict the flow.

I usually add a flush kit adapter to both hoses and flush the heater core by itself just to make sure it's flowing properly.

It is probably not the heater core do to most times when the heater core goes bad it stars putting water into the interior of the car. It may be the heater core supply valve or the blend door actuator is not working. Try warming the Vehicle, then carefully feel the heater hoses, are they both hot? If one is cooler than the other, You need to flush the core, or do a replacement job on the heater core. Also if the system has a heat control valve on the heater hose, make sure it is working! Also check the thermostat, and the temperature blend door, thats under the dash, in the heater plenum. You can flush this yourself, buy the prestone flush kit and install the tee in the heater return line. Disconnect the heater hose at the waterpump, clamp the hose in back of the tee you installed and back flush till it runs clear.20 mins or so.

I have had a similar situation myself and it was my heater core, on my vehicle it was a very time consuming job as i had to remove the entire dash to get to it. What you could try first if not tooo bad . Flush the system and reverse the hoses on the heater core and reverse flush. You can drive reversed for short time with the heater core hoses reversed as i did for over a week it may un plug if not as bad as mine was....Plenty of how tos on u tube to reverse flush your heater core and system.. I replaced my heater core radiator and water pump and a vent was broken in the dash i found and bad vacuum lines. a couple actuators were bad. had no heat to floor after doing all that it roasts me out of the truck, and the vents work properly including blowing on my feet the way i prefer.... Hopefully this helps you

Back flush out that is disconnected and connect mains hose to heater and power out keep revers flushing don't use Cir on alloy but u can get central heating flush that will work its called FERNOX system cleaner very good us this i system first run to work a few times then drain then reverse flush good luck iv used it very good

first it to verify the coolant flow. I suspect the heater core isn't flowing, you may need to take a garden hose and take both heater hoses off, and flush in both directions to clean the heater core. flush in both directions until you get clean water flow. I am assuming the coolant level is OK, and the water pump is pumping and the engine is getting warm enough.

Check heater core for 2 hot pipes. If they're hot, then the problem is in the blend door. If the 2 pipes are cool, then the heater core is plugged up and needs to be replaced rather than flushed, since flushing didn't help in the past.

Good luck on this repair.

you have air trapped in system. If you could hang van like a deer in a tee, you could get the air out. Go to a sho with evac/fill equipment and have them purge the air. You are about 3 qts short of full

go here too. read cooling system files.

http://groups.yahoo.com/group/villagerquest/

is the fan blowing if yes unhook the heat core to see if water comes out put a hose up to it to see if water comes out if so it maybe a heater value to

check coolant to ensure you dont need a flush also replace the thermostat.

Make sure the radiator is full. If so have someone back flush the heater core for you. After this it gets complicated......