Skip the auto shop - Our mechanics make house calls

Q: The front heater works only at high RPMs and the back only blows cold air

asked by on

My vehicle has an issue with heating. Actually, there are two separate heaters that are controlled separately. One is in the front and the other at the back. The back one isn't toatally unresponsive, but it doesn't heat just blows cold air. Whereas, the front works when the RPM is about 2500. Please give me some suggestions. Thanks.

A: There are two distinct possibilities: there...

There are two distinct possibilities: there is either no warm coolant to the rear heater core or a blend air flap is permanently in the cool air position. With no warm coolant to the heater core there will be no way to get the air in the hot air circuit. If the blend door is not moving in the rear climate control box, then air is only fed through the cool air side and not the warm air side.

A temperature check of the rear heater core will determine if coolant is being circulated through the core, and an inspection of the blend air flap and control on the rear climate box will determine if air being drawn through the warm air circuit. You may want to enlist the help of a mechanic, such as one from YourMechanic, who can diagnose and correct the rear heater circuit.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Someone ran a red light and hit my left front corner causing me to run right into them as they were still in front of me

Your car has one airbag (dual-stage) in the steering wheel center, which you observed had inflated along with the dual-stage passenger air bag. Some models (GS) had the option of having side air bags, stored in the side of the...

Q: Brake pedal hit the floor. Very hard to stop car.

First thing is you do not have any brakes and should not attempt to drive the vehicle until the brakes are repaired. The brake pedal is going to the floor due to a major brake fluid leak from the left...

Q: Key not starting car

Another key could be used to see if the lock cylinder will turn completely. Chances are either the lock cylinder itself or the lock cylinder housing is at fault. The may both need to be replaced to restore ignition operation....

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.