Question:  1992 Buick Lesabre V6_mileage: 102,000.  There never seems to be enough heat coming from the heater in this vehicle. I have changed the thermostat, and also had the radiator flushed; still just luke warm heat. Do you have any common remedies for this model vehicle 

Answer:  The heater core is like a small radiator inside your dash.  The coolant flow through it can be restricted by corrosion.  The lack of flow of coolant through the heater core will result in a lack of warm air inside the car.  Flushing out the heater core may help.  If not, you will have to replace it.  Also check the heater control valve if your car is equipped with one.

Question: 2002 Ford Explorer Mileage: 70,000. Three years ago, beginning of winter 2000, I could not get enough heat in the cabin. Cool air coming out of the heater, engine temperature not rising normally and often falling quickly. Thermostat clearly stuck open. A local shop replaced the thermostat and problem fixed, lots of heat again, normal engine temps. Price $38.97. Later that winter, Feb. or March the current problem developed. The engine temperature would quickly climb normally, but I didn't seem to be getting enough heat in the cabin. I put my hand to the heat outflow ducts and could feel ALMOST warm air coming from the left duct, but very cool air coming out of the right (larger) duct. This would continue for up to 15 minutes after the engine had reached normal running temperature. Then, whamo, plenty of heat came from both ducts. The engine temperature did not change when the heat would finally start to flow. I bit the bullet and took it to the Ford dealer. They managed to reproduce the problem. They promptly berated me for putting a non-OEM (original equipment manufactured) thermostat in the engine. They told me the thermostat was the problem and replaced it. I was charged $389.44. The problem continued with absolutely no change whatsoever. Can you help me solve this before another winter arrives?

Answer: Check to see that the blend doors are not hanging up in the heater duct. If okay, check the coolant level in the radiator, not just the overflow tank. Do this when the engine is cold...you don’t want to take the radiator cap off when the engine is hot. If your car is equipped with a heater control valve, make sure that it is operating properly.

Question: 2001 Ford Thunderbird miles: 54,980 My car blew a head gasket, just had a valve job, runs great until I turn on the heater, which is the electronic climate control variety, digital temp readout, etc. The heater blows hot air for a few minutes then turns cold. The engine temp gauge, which was in the normal range, before turning on the heater, begins to increase toward hot. The temp gauge returns to normal when I turn off the heater. The valve job mechanic and other guys are stumped, can you help?

Answer: Verify that the temperature gauge on the dash is accurate. Do this by putting a thermometer on the radiator. If this tests okay, check for air bubbles in the cooling system as you could possible have an air lock in the heater core or it is partially plugged.

Question: 2001 Dodge 1500 mileage: 38,000. Not much heat. Return line from heater core is cool, input line is hot. Tap water flows through core well, even ran CRL thru. Flushed system, changed stat, and even pump. Ran without thermostat, no better. Since there is no control valve and this has climate control, I don't know if it has an electronic problem or the core is still a problem. Looks like replacing the core is a complete dash removal. Can't find info on this type of system.

Answer: Test for a partially plugged heater core by testing the flow of coolant through the heater core. If it flows through easily then the problem is more than likely in the electronic heater controls or a stuck blend door.

Question: 2001 Ford Focus, miles: 86,000 automatic transmission. I didn't have any trouble using our heater to defrost the frost or snow on the windshield. The rear defrost works perfectly find. It was only 3 or 4 mos. ago that I thought of testing the heater, you know, in preparation for the winter season. That's when I got worried! Here's what I usually do: I would set the temperature towards the red part. Then, turn-on the front defrost switch. Select the fan to medium speed. Then, guess what happens! Smoke comes out! This continued until now! Then it was only two (2) weeks ago I noticed green stuff dripping to the bottom of the driver's and passenger's seats (not a lot to be noticed). You could see it if you looked closely and with the light on. And finally, I went to an auto repair shop, and as soon as I said, "smoke coming out of vents" then said heating core. So, the started computing an estimate and they came up with $201.84 (includes parts and labor and anti-freeze). I looked around to see if I could get a cheaper estimate. Do you have another suggestion on why it's smoking through the vents when the defrost or heater is switched on or do you agree with these people? In addition, do you think the estimate is approximately, close to what is acceptable or could you give me an accurate and least costly estimate?

Answer: It appears as if the heater core is leaking again. As for the estimate, prices vary from area to area. The best thing to do is check with friends and neighbors to find a mechanic you can trust.

Question: 2001 Dodge Dakoda Truck mileage: 65,000. My heat gauge goes the whole way to hot and blows out cold air then it will finally go down to normal and it will blow out heat when I pull in my driveway and let it idle it goes back up to hot. When it does that I look in my coolant bottle and coolant is pouring out the overflow I bought a new thermostat and it is still doing it I was told it could be my head gasket or the head but my car is not loosing power not smoking and not leaking water into my oil. So, I am not sure if it's the head gasket or head. Jimmy

Answer: 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.

Question: 1999 Toyota Camry mileage: 111,000. I am not getting much heat out of my heater. I recently had the thermostat replaced and a new water pump put in. The mechanic told me that there might be an "air bubble" blocking the flow of coolant to the heater core. I am also finding that coolant is always filling up the overflow bottle and spits out the hose that exits it. Only once in a while will I get very good heat. The heater core is in good shape and not leaking. I have had to add coolant a few times since the new water pump. I attribute this to the overflow bottle sucking out the coolant and spitting it out. There are no leaks anywhere with the cooling system either.

Answer: Check for exhaust in the cooling system as you may have a head gasket that is starting to leak.

Question: 2004 Ford Taurus mileage: 69,000. Heater is not working. A few weeks ago, it was working fine. Now when I turn the temperature dial from cold to hot it remains cold. I can feel the air change directions as I change from Def. to Def & heat. Nothing is wrong with the heater core, no leaks of any kind. Heater hose gets hot to the touch. I believe this is a vacuum or elec. problem. Could it be a damper is not closing or opening to force the fan to blow over the heater core vs. A/C? Not sure (can't see) where the vacuum lines are on these newer vehicles. Do you have any suggestions?

Answer: The air-conditioning heating controls are not vacuum controlled but are controlled by electric motors. You may be experiencing problems with the motor that controls the blend door. Also check the main control unit and all system fuses.

Question: 2002 Cadillac Seville mileage: 92,000.  Not getting any heat/air through vents but I am getting heat/air from defrost and underneath vents but not out of regular vents.  Why not?

Answer: The heat and air conditioning ducts are controlled by vacuum motors.  Check the vacuum supply from the engine to the heater/air-conditioning controls.

Question: 2001 Ford Windstar mileage: 80,000.  When I turn heater on, I get oil fumes through heater.  Have checked all oil compartments for leaks, changed oil pan seal, transmission seal and rear engine seal.  Valve cover gaskets checked head gaskets checked.  Get fumes when sitting still with engine running and heat on.

Answer:   The fumes may be coolant from a leaky heater core.

Question: 2001 Chevrolet 1500 Truck mileage: 95,000.  Unable to maintain engine temperature to 190 degree were I can maintain proper temperature for the heater and for engine.  If setting idle it will go up to 210, but when you go on the road for a test the temperature drops to 140 degree's.  Can you advise what is wrong?  I replaced the thermostat twice with a 192-degree thermostat.

Answer:  You may be having a coolant circulation problem that is possibly caused by the water pump.  We have seen the vanes on the pump corrode away to the point where there is very little coolant circulation.

Question: 2001 Ford Focus mileage: 83,000.  When I first start my Tempo in the morning it sounds like water running somewhere and I can smell anti-freeze.  I checked my anti-freeze level it is ok.

Answer:   The water running sound that you hear is probably caused by air in the cooling system.  As the air and coolant go through the heater core, it will make the sound you described.   The anti-freeze that you smell is probably from a leaky heater core.  You mentioned that you checked the anti-freeze level and it was okay.  Was this done in the radiator or in the over flow reservoir?  The radiator should be checked, ice cold and clear full of coolant.

Question: 2003 Chevy S-10 Blazer mileage: 44,754.  I have a 1996 Chevy Blazer 4x4 with a V6-262 4.3L engine.  About three weeks ago, the heater stopped blowing heated air.   Having a father that teaches automotive technology we decided it must be the thermostat.  We replaced thermostat with no success.  Blower works fine.  Coolant level is good.  Connecting the scan tool the vehicle temperature only got to 195 after extended running time.  Unable to find any info on normal operating temp.  For a Blazer we are at a loss.  Using the fix of old, we placed cardboard over the radiator and that seems to make it work better not great.  With the problem possibly being the heater core or actuator with a dealership repair cost of $500.00 I am no doubt frustrated.  Do you know of anything else that we might try or any problems that you have heard about Blazers cooling system?  There are no recalls to date on all data.  Any suggestions would be appreciated.

Answer:   Two things to check: First check for vacuum that goes to the heater control, you may have a loose or cracked line which would cause the heater doors not to work properly; Secondly, check for a partially plugged heater core that would restrict the coolant flow.

Question: 2004 Plymouth Voyager mileage: 89,000.  Would too much antifreeze cause my vehicle to blow cool air from my heater?  It works fine when in park, but it and the car cool down when driving.  The needle goes back to cool also.

Answer:   Too much anti-freeze would not cause cool air to blow from your heater.  Your problem is probably with the engine thermostat; it is either stuck open or it is too cold (160�) and should be replaced with the proper one for your car.

Question: 2001 Nissan Altima. The heater stops working when the RPM slows down.  As long as she is running around 65 miles per hour, it works.  If she slows down or has to stop, it stops.  Any idea what this might be.  She has a small baby and needs the heater working badly.  We have asked everyone, nobody seems to have a clue.  My husband thinks it may be the vacuum.

Answer: Check coolant level you may have a coolant leak. Also heater core in your car is partially plugged or restricted nearly stopping the flow of coolant through it.  Flushing it out or replacing it should correct her problem.

Question: 2002 Toyota Camry mileage: 85,000.  Heater will not get hot. Temperature gauge is normal.  Air is just barely warm.  Have replaced thermostat, vacuum control switch in dash and heater core.  Have bypassed the valve at the firewall.  Water hose to heater is hot to the touch.  Return water feels cooler to the touch.

Answer:  Sounds like you are having trouble with the doors in the heater duct not opening properly.  You might want to check the vacuum supply to the heater control switch in the dash.

Question: 2000 Chevrolet Cavalier mileage: 86,000.  I recently had problems with the heater in my car.  I keep blowing fuses for my heater...we tried to replace the fan thinking that was the cause but no go.... all the other fuses are working fine its just the heat...can you think of any other problem?  The only heat I am getting is when I get driving it automatically flows through the vent and baby it is cold outside in NY.

Answer:  You need to perform a couple of tests.  First, disconnect the power wire to the heater fan and turn on the controls for the heater to see if it blows a fuse.  If it does, then you have problems in either the wiring or the control on the dash.   Second, check the variable speed resister.   It is usually located in the air duct close to the blower motor.  It is possible that it has shorted out.

Question: 2004 Honda Civic mileage: 39,000.  Heater is not working properly.  It starts out blowing hot then gets cold.  Head gaskets were done recently.  New thermostat installed.  Heater core flushed.  Radiator only 6 months old.  Temperature gauge is also erratic.  Intermittently goes to hot then comes down to normal range.  I cannot figure this out and neither can my mechanic.  I need your help desperately.

Answer:  We think your problem is a low coolant level.  With the engine cold, and we mean cold, open the radiator cap (not the overflow cap) and it should be clear full.  If not, fill it to the top.  Over the next couple of days, check for coolant leaks under the car when parked.