Q: Heater is blowing cold air truck is overheating and now I reduced power engine power light is on

asked by on November 28, 2016

heater is blowing cold air truck is overheating and now A reduced power engine power light is on I have replaced the thermostat but all the issues still continue
My car has an automatic transmission.

Heater is not working Inspection $94.99 - $114.99 Get a Quote
Thermostat Replacement $157.20 - $759.78 Get a Quote

The heater not working in some cases may be related to the overheating problem you are also having. This may be due to a faulty heater blower motor or potentially a bad heater core. As you may know, the heater core is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. When the cooling system is not properly circulating coolant through the motor, this results in the warm coolant not being pumped through the heater core properly in order to warm the inside of the vehicle.

Engine overheating can be caused by a number of things such as low coolant levels, a faulty thermostat, or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this switch is not working properly, this can cause the fans to come on intermittently, all the time or sometimes not at all. When this happens you will notice a temperature spike and drop occasionally as the fan comes on and off. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. As mentioned above, this also restricts the warm coolant from flowing through the heater core which uses this to blow warm air into the cab of the vehicle. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Car hard to start when warmed up
This is a very interesting problem. Usually cars are harder to start when cold. There are many reasons why this could happen. The most likely cause is that one of the electronic modules or sensors are starting to break down...
Check Engine Light came on
It sounds like you have a pretty bad misfire. While a faulty O2 sensor could be the cause, it is not the most likely. A misfire happen can be caused by anything that prevents the air/fuel mixture from igniting properly...
Car making humming noise when driving, but when I stop at the ref Light I don't hear the sound. Also when I go over 40mp get loud.
Hi and thank you for contacting YourMechanic. The problem seems to be either a wheel rubbing brake rotor (https://www.yourmechanic.com/services/brake-rotor-disc-replacement) for the lug nuts not being tight enough or a wheel bearing that is worn out. The noise occurs only when...
My ABS light and occasionally my emergency brake light is coming on and my brakes occasionally make a grinding noise when coming to a stop.
Hello there, many faults will cause your ABS light and emergency brake light to be seen on your 2009 Chevy Aveo5. When the ABS light is on it indicates there is a fault in the ABS system. This fault will...
No heat in car and engine light on for overheating
Hi There, Your heating issue may be due to a faulty heater blower motor or potentially a bad heater core (https://www.yourmechanic.com/services/heater-is-not-working-inspection). As you may know, the heater core is a small radiator like unit that circulates the hot coolant from...
drone sound only when turning the wheel to change lane or exit ramp (on any/all road surfaces)
Hi there. It sounds like there could be a rear wheel bearing causing the drone. Has anyone checked the rear wheel bearings? They may have gone overlooked due to the front wheel bearings; it does happen. I suggest having a...
My dashboard lights,gauges,radio and power windows don't work. I can start my truck right up and drive.
Hello, thank you for writing in. Typically with the first symptoms you described I would direct you to check all of your fuses, focusing on the instrument cluster fuse. However considering the engine is showing signs of stress, you may...
Another mechanic I asked said I had leftover bolt that went into the water jacket and now I need to replace the heads... is this t
Hi there. Unfortunately we don't enough data from you to answer this question. We need to have the year, make and model of vehicle and the identification of the services completed to give you a good answer. Thanks.
I change the thermostat and water pump and it still overheating on a Chevy Suburban 2006
Hi Alfonso. Usually when these repairs are completed and you still have an overheating problem, it will be due to one of three things. First, it could be due to an air bubble trapped in the cooling lines. This tends...

Related articles

A Buyer’s Guide to the 2012 Chevrolet Suburban
The The 2012 Chevrolet Suburban offers large amounts of space to carry around a growing family or to transport supplies to your favorite camping spot. It is available in heavy duty and half ton models. Key Features The 1500 Suburban...
Symptoms of a Bad or Failing Electronic Ignition Pickup
If your car has an electronic distributor ignition system and the engine stalls or car does not start, you may have to replace the ignition pickup.
How to Buy a Classic Chevy
For experienced car collectors and rookies alike, owning a classic Chevy is a rite of passage. There are multiple decades and styles in which Chevrolet made popular cars. Many of these cars then had a devout following in the years...