Skip the auto shop - Our mechanics make house calls

Q: Car keeps stalling when I press on the brakes

asked by on

I have replaced water pump radiator and thermostat. Because it was overheating. Just to find out there was air in the system. I bled it. Now every time I put the brakes on it will stall. I just don't know what's going on. I'm confused.

My car has 205000 miles.
My car has an automatic transmission.

Your car has a unit in the fuel injection system called an idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature, and electrical system load or voltage.

When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. This is all done by the idle air control valve. When the engine RPM drops below the normal range of 750-800 RPM (for most cars), this may indicate a dirty or faulty idle air control valve. In cases where this valve is dirty or failing, your vehicle will stall instead of slowing to an idle after the release of the throttle as you have described.

To avoid any unnecessary repairs, I would recommend having an expert from YourMechanic come to your location to diagnose your stalling issue and repair your idle air control valve as necessary.

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: How do I turn off the panic alarm?

There are two different ways to turn off the panic alarm: 1. Use the remote keyless entry (RKE) transmitter. The panic alarm button on the RKE transmitter turns on the panic alarm, and it also turns the alarm off. Press...

Q: Car shuts off unless the gas pedal is applied

The coil should be generating tens of thousands of volts to the spark plug. 12 volts is the correct supply side to the coil. It also sounds like you still have a fuel problem. Have a professional mechanic check the...

Q: My car cranks but won't start.

Hello. Wiring from the ECU to the engine should be checked. If no signal is getting to the ignition module, there can be a short in the engine harness or a bad ECU. If you need help having this addressed,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
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...