Q: Whats causing my car to cut off in slow moving traffic

asked by on

Whats caising my car to cut off in slow moving traffic and when it does my car sarts write back up.only happens when driving in slow traffic

This is a common sign of a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. In your case, when driving in slow traffic, if this valve is dirty or faulty it may struggle to maintain the proper air/fuel mixture resulting in it stalling as you have described. Since this valve is controlled by the vehicle’s computer, it 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 with the help of the idle air control valve. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your idle air control valve.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Whats causing my car to cut off in slow moving traffic

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: Possible valve seat loose

The valve seat is a part of the cylinder head and can not come loose. It is possible to have a broken spring, bent pushrod, or maladjusted rocker arm. This is all work that is associated with the repair you...

Q: Car idling high in park

At such a high idle speed, a large vacuum leak would be possible if the engine didn't return to a normal level after warming up. The idle air control valve regulates engine speed when the throttle plate is closed, allowing...

Q: Truck idles rough

This is a sign of a failing idle air control valve. This is a unit that is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected into...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.