the heating costantly blows cold air even when on full the air conditioning works perfictly
2006-10-19 22:02:56 · 4 answers · asked by jayjen82 1 in Cars & Transportation ➔ Car Makes ➔ Ford
Check hoses going in and out of the heater core (hoses that go into the firewall on right side of the car!) If they are both hot, then water is going through the heater, and you have a "door switching problem", If not, - then either the heater core is blocked, -the cooling system is low on water, - or the heater core is airlocked, -( this can happen if the pressure cap is not working properly). Also it is possible, but not likely that you have a "shutoff valve" in the heater line which is not opening. If this is the case, it will be hot on side going to the valve from the engine, but not near as hot(if not just warm from engine compartment temperature) on the other side of the valve!
Practically all cars have vacuum operated heat control systems to switch doors, - (which control where the air goes through). It is likely that the "door" sits on a/c when there is no vacuum applied (or it may be a neutral module, and a/c is where it was when the vacuum died). If you now have no vacuum going through the control, (or the vacuum switching control on the dashboard is bad), - then no switching will ocour. Or the water control valve outside might not be working,- (because of no vacuum to operate it!)
If you have a hose pulled off somewhere, and the engine isn't too noisy, - you should be able to hear a a "sucking noise"
where the hose is broken or pulled off, it may also sound like a high pitched whistle (depending on size of the hole). Most cars don't have the heater valve, - so there is a door inside the heater that simply moves over the airconditioner core (or opens the heater door) so air flows freely through the heated core (a little radiator like thing).
If you have a vacuum leak, and it is big enough, it will also affect the way the engine idles, -(especially when cold)! So this might be a clue that you are observing also!
A very rare occourance is when the heatar core gets "airlocked" -in other words, - the water isn't flowing through the way it is supposed to, - and there is air sitting there instead! This can be caused by bad pressure cap, - as the water pressure increases to about 12-13# on most cars when hot, the pressure compresses the air, and generally will push it through!
It isn't hard to check the heater core for blockage, - just remove the heater hoses (either end, as long as you get both off)- be sure you do this with "cold engine", -then you won't get burned from hot water! At this piont you can run a water hose to either side, and turn on water, - it should push water out the other side. It will also push out a bunch of "gunk" out on the other side as it cleans out all the loose stuff with the "higher pressure" and faster flow of water.. It would be good deal to reverse ends several times while you have the hoses off of radiator, -- to flush as much out of heatrer as possible, (which will make it more efficient in the future!)
If this doesn't get you fixed,- you will need a garage mechanic to take care of it!
2006-10-20 02:31:38 · answer #1 · answered by guess78624 6 · 0⤊ 0⤋
Check your thermostat first, it's the easiest to get to.
If that's ok then look to the heater core it may be plugged up.
Finally check to see if the door that redirects the flow of air is opening to the heater core. If the car is not over heating then the
last two suggestions are more than likely the issue
2006-10-20 05:13:22 · answer #2 · answered by peacemaker9864@sbcglobal.net 1 · 0⤊ 0⤋
how old is it? could be the heater core is clogged, the thermostat is not closing, a side vent might be open letting cold air in.
2006-10-20 05:09:05 · answer #3 · answered by oldguy 6 · 0⤊ 0⤋
cable that opens vent door also vacuum was used . what is a ford ka ?
2006-10-20 05:14:52 · answer #4 · answered by martinmm 7 · 0⤊ 0⤋