Car Heaters

Sounds like you have a problem with the air door actuator that switches it from hot to cold. That car shouldn't have a heater control valve, instead it uses an actuator that moves a door which directs the air flow to either flow through the heater core or bypass it. If coolant is circulating through the heater core, and nothing is stopping the fins on the core up, then you have a problem with either the actuator or the door itself. When you switch it from hot to cold do you hear something moving on the passenger side of the dash? If not, it is probably the actuator, or it could even be the control panel.

On a 87 Jeep Wagoneer Limited 4x4, 242cid 4.0L, M.O.H.V. - M, it is located under the kick plate on the passenger side. Unscrew the plate and you will see the vacuum motor (which looks like a flying saucer) and to the left of it you will see the resistor. Unplug the four prong wire, and unscrew the two screws holding it in the duct, and lift out. (Takes about ten minutes to remove)

air in the cooling system. some are hard to bleed. I've had to jack the car up sometimes to get the radiator fill at the highest level possible. you have to get the air out of the heater core and this problem will be fixed. you might try loosening the uppermost hose at the heater core until coolant comes out. there might be a special proceedure for bleeding this system also.

If the fan isn't blowing, check the fuse. Consult your owners manual for its location. If its not the fuse, its probably the switch or a relay. Take it to a mechanic.

If the fan goes like crazy, but very little or no air comes out. It may be the air filter is clogged. Consult your owners manual for its location or if you like, those Jiffy lube guys can usually replace it for you.

If the fan blows fine but its not blowing hot air....

Check your coolant!

Nine times out of ten, when someones heat stops blowing hot air, it is because they have neglected their cooling system and there is not enough coolant flowing through the system for it to fill the heater core. Driving the car in this condition can damage the engine. Check your antifreeze and fill it up.

SAFETY TIP: NEVER open a radiator cap when the engine is hot! Wait until the cars cools before you check your coolant level.

Some of the dangers of using an indoor air heater are that in houses poor indoor air quality can result in a structural rot. Also, indoor air pollution may occur which is not very talked about.

Low coolant? Wrong thermostat temperature range? Heater core plugged,restricted or airbound? Water pump not circulating coolant? Temperature control cable not adjusted properly?

if you are talking about engine overheating possibly you have problem with your cylinder head. sometimes due to natural wear and tear gasket in the cylinder head got blown and the pressure of the engine is going inside the cooling system making the engine to overheat since when the pressure is high water from the radiator will be expelled to the radiator reservoir causing overflow that lessen the cooling water inside the engine. you can check it by having somebody start the car ( while engine is cold ) prior to start up remove radiator cap, upon start check if the water in the neck of the radiator opening will spill out. if it does probably you've got a blown head gasket. Have it replace by your mechanic. have the mechanic check also the thermostat of your cooling system, there's probability that it is not working properly. Have the water pump also be check whether it is still working or not. Have the clutch fan be check for its proper operation. You can check it while engine is cold, rotate the fan blade of the radiator fan. if the clutch fan is still good it should not turn half of its radius. if you can easily turn it then its time to replace it.

May have air in the system. You will have to bleed all the air from the vehicle. Sometimes jacking up and supporting the front end while rev'ing the engine at about 2000 rpm and adding coolant till it's full will work. Be sure to install the rad cap while engine rpm is still high.

Do this with the engine at normal operating temp.

Is this a 2003 Pontiac Bonneville? I need this answered for this year and make.

Low coolant.

verry common problem its the heater tap stuck open, you can do a quick fix and bypass the heater, but than you wont hav a heater when its cold of find the tap and close it manually, so i recommend that you replace the heater tap

Near the firewall under the hood, there is a little vacuum hose that has a plastic disk looking thing in the hose. This piece actually has to do with an engine backfiring, but that disk thing is probably cracked from heat and age. Needs to be replaced. If that is okay or you can't find it, Look for a vacuum hose going into the firewall, follow it to the intake and make sure it has vacuum. If it does, then the problem is inside the car, probably has a leaking vacuum line behind head unit or needs a head unit.

First thing to check is the coolant level. It can be low and keep the heater from getting warn and still not make the car overheat. If it's full, too cold a thermostat. Worst case is a partially clogged heater core. A collapsed heater hose possible.

why dont bottom vent doors not open on 2001 gmcsonoma

Low coolant? Bad thermostat? Heater core plugged,restricted or airbound? Heater control cable or valve not working?

because maybe you car is either broken or the cold air is coming in from the outside

With my car, it was Heater matrix clogged with radiator sealant. The workshop cleaned it and it's start working fine!

Jaguars, depending on the model, have a seperate pump for the hot water for the heater. It's located on the left front inner wing, it is difficuult to see and remove. This is the most common problem on XJ40, X300, X305 and X308 shape jaguars. Same pump is used on X and S type too. Cost between £35-3&0 on ebay.

I've been trying to find this out too (for a mark III Golf). The smell's more noticeable in heavy traffic, I sometimes see smoke coming out of the air vents when the air's not switched on, and find condensation on the windscreen.

It seems to be a problem with the cooling system. The coolant leaks onto the engine where it's burnt off. Maybe the heater core?

If engine is not reaching operating temperature, then replace your thermostat. If the engine is getting hot, feel both heater hoses ( passenger side they go thru the firewall) they should both be hot, if only one is hot, your heater core is probably plugged and should be flushed. I hope this helps you. Mark

Because the blend doors are stuck in the wrong way == If the fan is still blowing air,check your thermostat.If that doesnt fix it check the control valve under your hood(if your model has one). last,but not least, check your heater core. if both in and out hoses are hot when car is warmed up, its supposed to mean it's ok.( if not, you'll need it replaced) Good luck!

Some heater/defrost controls are mechanically controled and some are vacuum actuated. Look under the passenger side dash and see if you can locate the means by which the flapper is controlled. Normally the flapper just redirects the heated air from the rotating fan to eith go out the vents or up to the vents in the defrost. Most mechanic units (attached by cables from the dash control unit) do not break or wear out. The vacuum operated ones sometimes the small vacuum hoses that attach to a solenoid come off or get brittle and loose their seal against the plastic tips. If you can work the dash controls while you look under the dash and try to see how and why the flapper is not moving, then maybe you can ascertain how the flapper is actuated. Last resort OS to try to remove the in dash control unit. It will either have the mechanical cables attached or vacuum lines attached to it so be careful when removing. Once you control the flapper in the air box, then you norally can redirect the air to where it needs to be. Look for a cracked vacuum line by the master cylinder. There are several that interconnect which feed through the firewall and into the dash that supply all of the dash vacuum.

It sounds like it may not be working at all. Does the warm air get warmer that the ambient air outside your car? Does it get colder than ambient air in the cool cycle? It sounds like it is just passing the outside air through the blower but doing nothing to it. Possible blown fuse in the fuse box under the dash or in the fuse box under the hood.

If it does get colder or warmer at the outlets of the AC system, then you could have a couple of wires reversed, or another problem that requires on site inspection to find. Take it to a repairshop.

The problem you have sounds like a vacume leak, most likely under your dash, in your heater control tubing. As your driving speed increases, so does the vacume created in your intake manifold, and as your heater control is vacume actuated, it is affected by engine RPM's. Look for a loose fitting, or a tube joint that has come apart under the dash first. Start the car, listen for leaks, you could even blow smoke around the lines to see the smoke get sucked into the loose fitting. If nothing under the dash is found, the vacume leak may be elsewhere, but that usually causes a rough idle too. Hope this helps! W. Cook Canada

it does not have cable, it is vaccuum and acuator motor driven

Heater motor switch and or the connection at the switch is melted. Also check connections at the blower motor and blower motor resistor for melt down damage.

It is under the dash board and it is extremely difficul to change. Shop labor and parts will cost you aroud $350.00. I just had mine replaced. It can be done, though. Took me six hours, three of which were the stupid dash. You'll see the two hoses in the middle and the bottom of the firewall.