1998 no heat coming from heater?

Question

Waater pump had a leak, so I replaced it. I bleed the car and still no heat and it was overheating, than I replaced the thermostat and same thing, no heat, it not the heater core, and when I drive the heat will eventually come back on but soon as i stop so will the heat. Can someone please help me I don't know what to do.
Thanks

Answer 1

i own a repair shop,and maybe whats happening to it is its air locking on you,they,ll do this if you refill them with the heater cut off on it,i usually refill them while there not running and then start them ,,turn the heater on full blast fan and all and let it run for a good 20 minutes ,and then add the the reservoir tank on it,,it will take in what ever amount it needs to fill it,and send the extra back out to the reservoir on it,this has worked for me for a long time,i hope it might help you get heat,if not you may have a bad heat control valve on it,this is what separates heat from air conditioning on it,good luck,i hope this help,s.

Answer 2

first things first. make sure both heater hoses going into the firewall to heater core are hot after engine has warmed up. if so it could be a vacuum leak to your heater door under dash. this would explain no heat while at idle because not much vacuum but while riding along more vacuum to heater door causing it to open. listen for a hissing sound under dash or on passenger side of engine compartment.if all is good there next possibility are the vains in your water pump could be worn or damaged,not likely but i have seen it a few times in my line of work. check this by removing one heater hose start car,plenty of pressure and volume not the problem.at a idle the water pump pumps less.going down the road water pump spins faster more water to engine more heat. the only other thing that i know of would be a head gasket starting to fail on engine. this would allow combustion to form a air pocket in engine block at idle but with higher rpms water is forced threw the air pocket filling the air space. check this by having your mechanic put about 120lbs of air into a cylinder at the time with both values closed. check for bubbles into radiator system. hope this helps a little

Answer 3

Also so check for a blocked heater core. You didn't say if you corrected the overheating problem or if the heater was working before you did the repair. If the heater core, disconnect both heater core hoses and do a reverse flush to see if this helps before replacing the heater core.

Answer 4

Bad water pump,how do you know the heater core is good.get motor hot turn heater on run hand on heater hoses both should be hot.Does fan work,does controlls work This is a 1998 what kind.Does it have air in system .Does it have a bleed orr next the thermostat houseing.Sure they gave you right water pump water go the right way.Dont know what kind of car or truck,Do they put the motor you have in a boat they turn back the other way.Dont know what you got.

Answer 5

you have a heat control valve tied in between your hot side hose coming from the water pump feel the hose on both sides of the heat control valve make sure it is hot on both sides if not thats your problem replace it. and you will have heat. this valve when heater is turned on lets the hot water pass thru to the heater core and if it doesnt open you will not have heat.

Answer 6

Is the blower working? If there's no heat when you're stopped but it comes on when you move, it sounds like the blower is bad. Ram air gets forced through the heater core when you move, giving you some heat. When you're stopped, no ram air, so no heat.

Answer 7

is your shutter door moving from cool to hot ,have a vaccume leak? if not how sure are you on the heater core your story sure sounds like a heater core doesnt have to leak to be bad.

Answer 8

bleed the air out lower back. bypass away the cap off with the heater on finished. worry-unfastened for human beings to bleed the gadget with the heater off. and air gets caught interior the gadget inflicting it to not artwork.