Q: Heat only works when accelerating

asked by on

The heat only works when accelerating had a coolant flush thinking that would help it did not . They did bleed it the right way twice the heat works for about 20 mins then goes back to only when giving gas . I changed out the thermostat for a different reason but the problem was still accruing also had the radiatior changed then had it bleed about 6 months ago now it's cold had it bleed twice and still having the same issue

My car has 129000 miles.
My car has an automatic transmission.

Hello. I suspect the heater control valve is the culprit here. Most likely only opening partially. By only being partially open, it allows more hot water to circulate when the engine load and RPM are higher, as when you accelerate, but not enough otherwise. Another possibility it that the heater control mechanism (most are electric these days) is not signaling the air blend doors. The circulating air controls which "mix" cool and hot air before it comes out of the vents - resulting in too little hot air coming out of the heater ducts. If you would like to have this taken care of, I recommend having a certified professional from YourMechanic come to your car’s location to inspect the heater system and proceed with any needed repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Heat only works when accelerating

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: I own a 2004 Land rover Discovery SE7 the heat works when \i drive it however when it is \idle the air blows cold I noticed my coo

Hello. Thank you for writing in. The heating system depends heavily on the function of the cooling system. What is likely happening is a lack of coolant circulation when the car is idling. This is causing the coolant to sit...

Q: I have a 2014 Nissan Murano 62,000 miles. I took it to Courtesy for the power steering hose recall. I decided to get my oil change

Hi there. One of the techniques used by professional mechanics to test a power steering system installation or replacement is turning the wheel quickly to one side and the other, to verify that no air bubbles exist in the system....

Q: Q: Leaking head gasket

Any type of head gasket sealer is only recommended to be a temporary repair in most cases. I see some claim to be a permanent fix. I do not believe any of these any of these sealers will seal permanently....

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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.