Car Only

There are several reasons why your car’s heater may be blowing cold air, instead of heat. It is important to understand how the heater works in your car before you can begin to try to diagnose why it is not working. First, there is NOT an electric heater element in the heater system in automobiles, like in portable heaters used in the home. The part that transfers heat into the passenger compartment is called a heater core. A heater core can be thought of as a miniature radiator. The car engine’s coolant flows through the heater core while the fan (also called a blower), blows air through the heater core fins. When air blows through the heater core fins, it is warmed, therefore warming the passenger compartment.

Start by checking the coolant. As we already said coolant is what warms the heater core. So if the coolant is low, there may not be a sufficient amount of warmth to transfer heat to the air in the passenger compartment. Since it ’s cold outside, low coolant may not effect the operating temperature of the engine significantly, so you won’t be alerted to a coolant problem by the temperature gage on the instrument panel. Once the coolant is full, feel the heater hoses that go through the firewall. With the engine at normal operating temperature, BOTH of the heater hoses should be hot to the touch. If only one is hot, this indicates there is is a blockage in the heater core or there is air trapped in the heater core. Using a Lisle coolant funnel is helpful in purging the air from the cooling system. If the coolant is really brown, has been neglected, or if “stop leak” has been used at some point, the heater core could be stopped up. The blockage can sometimes be unstopped by removing the heater hoses and using a garden hose with a sprayer to flush the heater core out. If neither of the hoses are hot to the touch, there could also be a malfunctioning heater control valve, if used on the model you’re working on. Check for presence of a heater control valve by following the heater hoses back to the engine. Sometimes, a vacuum line could have a break causing there to be no vacuum to operate the valve. Also it should be noted that if this is your first winter with this car (and you’re unfamiliar with the car’s repair history), the previous owner could have by-passed the heater core because of a leak. When a heater core leaks, usually they wet the passenger side floorboard. The labor cost to change heater cores is usually expensive, so sometimes people will loop the heater hoses and by-pass a leaking heater core instead of repairing it properly.

Next check for proper airflow. After you’re sure the heater core is getting hot water flow, read the following information. Doors within the heater case are either controlled by electric actuators, cables or vacuum motors. Adjust the heat control to both extremes while listening for movement of the blend door. With a cable operated heater door it’s easiest to hear the door thump when it closes. If the door is not operating, find the door that controls the airflow across the heater core. If there is an electric motor that controls the door, tapping on it can sometimes make it work temporarily for testing purposes. A vacuum operated motor needs vacuum to work, so using a handheld vacuum pump for testing is usually recommended. If the vacuum motor does not hold vacuum, the diaphragm is leaking requiring replacement. To go deeper into diagnoses of the control head’s function and diagnosis, specific vehicle repair manual information is needed. But hopefully the basics laid out in this article has helped to get you started on the right track. 

About the Author. Hi I’m Dennis Bandy, thanks for reading about my background. I’ve been an ASE Master Auto Technician for over 23 years and have also sold professional auto tools since 2005. I am in a unique position to help readers on certain automotive repair related topics since I’ve had personal hands on experience with many auto repairs and automotive specialty tools. Let me just say, this is not a hobby for me, this is my business. Your feedback is really appreciated, if you thought this article was helpful or informative, please rate it below (thank you in advance).

Half the battle when it comes to auto repair is having the right tools, that’s why we have supplied name-brand automotive tools (like OTC, Makita, Ingersoll), shop supplies and automotive shop equipment at discount prices, at DenLors Tools since 2005, many readers put us on their favorites list and visit our site when auto specialty tool needs arise, we hope you do the same.

Is there some type of one time only Mexico travel insurance for your car?

Is there some type of one time only Mexico travel insurance for your car? I am going to Tijuana for a weekend and my insurance company only covers until 50 miles out. I hear that there is some type of car insurance that Mexico offers? Does anybody know about that? I mean specifically for theft prevention. Thanks!

There’s a little shop where you can get it right before the border. Look for the signs. It costs about $30 for a day.

Cadillac : CTS 2004 Cadillac CTS-V Navi Sunroof FL Car Only 37k Miles! $21,290.00

Lincoln : Town Car SIGNATURE 2002 LINCOLN TOWNCAR SIGNATURE W/ONLY 48K MILES 1 OWNER $6,900.00

Lexus : GS GS350 08 GS350, LOADED, IMMACULATE CAR!, ONLY 15k Mi., 1-Own! $34,500.00

Chrysler : Concorde CASH CAR! IT DOES HAVE A CLEAN CARFAX – YES … ONLY 38K MILES! $3,991.00

Jaguar : RHD SEDAN FOUR DOORS RHD MK2 ONLY FOR RESTORATION – CALIFORNIAN CAR PAY ONE GET TWO $6,500.00

Nissan : Maxima GLE GLE! ONLY 37,959 MILES! GORGEOUS FLORIDA CAR!LOADED!N/R $6,088.90

Maserati : Quattroporte 4DR SDN ONLY 30K MILES, GREAT OPTIONS, NAVI, CA CAR, MUST SEE!! $26,100.00

Lincoln : Town Car LIMO SS L 2009 LINCOLN TOWN CAR SIGNATURE L ONLY 10K MILES!!! $16,100.00

Mercedes-Benz : S-Class 2005 Mercedes Benz S430 w/ only 44k miles Very Nice Car $15,000.00

Aston Martin : DB7 VOLANTE V12 V12 CONV ONLY 6K MILES LOADED! ALOT OF CAR FOR LITTLE$$ $49,000.00

Ford : Mustang SHELBY GT500 ONLY 800 MILES ON THIS NEW CAR TRADE-540 HP GT-500-WOW $37,309.00

Porsche 959 S 1 of only 29 cars with the Factory Sport Package $495,000.00

Chevrolet : Camaro IROC Z IROC Z CONVERTIBLE SOUTHERN CAR WITH ONLY 59,000 MILES! $3,383.33

Kia : Amanti Kia Luxury car , Arizona car history only $2,425.00

Aston Martin : Vanquish 04 VANQUISH, PRISTINE CA CAR, ONLY 10000 MILES!!! $38,988.00

Lincoln : Town Car DE LUXIE 1989 LINCON TOWN CAR VERY CLEAN — ONLY 56K — ORIGINAL $1,500.00

Mercedes-Benz : SLR McLaren SLR 06 SLR MCLAREN, COLLECTOR CAR, ONLY 1900 MILES!!!!!!! $65,100.00

Ford 1933 Ford Tudor Sedan Body Only California Car $3,050.00

Lincoln : Town Car SIGNATURE 92′ LINCOLN TOWNCAR ONLY 43,000 ORGINAL MILES!!!!!!!!!! $3,000.00

Mercedes-Benz : S-Class S-430 2000 S-430 GOLD/TAN***ONLY ONE OWNER** GREAT CAR!!! $5,100.55

Honda : Accord EX Sedan 2004 ACCORD ONLY 28682 MILES ONLE OWNER LOCAL CAR CLEAN $5,000.00

Ferrari : 355 Only 20K MI. 1997 Ferrari F355 Spider, California Car, As New Cond. $29,100.00

Bentley : Azure 2008 Bentley Azure w/ only 700 miles… Amazing Car $160,100.00

Maserati Cambiocorsa 2006 MASERATI COUPE CAR CAMBIOCORSA 4K REAL MILES ONLY! $49,900.00

Chevrolet : Camaro 2DR CONVERTI 2000 Chevy Camaro SS Convertible Show Car Only 16K Mi $1,075.00

Ford : Thunderbird T BIRD 78 FORD T BIRD GREAT RUNNING CAR ONLY 76K MILES CLASSIC $1,500.00

Acura : Integra LS, 5 Speed 360 Video Tour! Safe Car Only 2 Owners! $4,750.00

Kia : Soul Soul+ 2010 KIA SOUL + BASICALLY A NEW CAR-ONLY 17 MILES ON IT $16,388.00

Aston Martin : DBS 09 DBS SUPER CAR, PRISTINE, ONLY 2400 MILES!!! $33,433.00

Chevrolet : Corvette 1972 COEVETTE LT1 A.C CAR 1 OF ONLY 240 LOADED $59,900.00

Mercury : Grand Marquis LS 2002 GRAND MARQUIS W/ONLY 32K MI MINT COND FLORIDA CAR! $7,500.00

Mercedes-Benz : SLK-Class 98 MBZ SLK 230 ONLY 34K !!! HARD TOP CALIF CAR CLEAN!! $2,000.00

Mercedes-Benz : S-Class SPORT WE FINANCE! $3K DOWN ONLY $682 A MONTH! BEAUTIFUL CAR!! $38,000.00

Mercedes-Benz : E-Class Sport WE FINANCE! $3K DOWN ONLY $436 A MONTH-MINT CAR LOADED! $28,000.00

Pontiac : Trans Am Rare Indy Pace Car, Highly Documented, Only 46K Miles $24,995.00

Chevrolet : Corvette 1978 Corvette “Indy Pace Car” Only 4,516 Made $8,000.00

BMW : 3-Series CONVERTIBLE FLORIDA CAR ONLY 62K MILES JUST INSPECTED & SERVICED! $2,125.00

Rolls-Royce : Silver Shadow  1976 SILVER SHADOW FL CAR ONLY 44K MILES $29,900.00

Mercedes-Benz : SL-Class 1998 MERCEDES SL500 ROADSTER, ONLY 91K MILES! NICE CAR! $12,495.00

Ford : Mustang MACH 1 2004 FORD MUSTANG/ MACH 1/5 SPD/ NEW CAR!/ONLY 30 MILES $26,500.00