Skip the auto shop - Our mechanics make house calls

Q: Car jerking when slowing down

asked by on

My car sometimes jerks while I'm driving it feels like it's about to die on me. It mostly does it when I'm slowing down. I just got my spark plugs replaced thinking that would solve the problem. But it's still happening.
My car has an automatic transmission.

This is a common symptom of a dirty or failing idle air control valve. As you know, 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. As 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 (for most cars), 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 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

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 need to replace plugs and wires and need to know how far forward I can roll the engine with an awd driveshaft and pto?

I would consult your Owners Manual for specifics, but most manufacturers provision the vehicle to be towed short distances at slow speeds safely. The important factor here would be that all 4 wheels are rolling the same speed (i.e. now...

Q: Rom is running high in my truck

Hello. This is a sign of a vacuum leak. A vacuum leak can be one of the most frustrating and difficult problems to diagnose. Idle speed that is way too fast is one of the common signs and stalling is...

Q: I have a problem with my 2000 honda civic. It does if like it runs out of gas but i have full tank.

You may have a "missing" (misfiring) cylinder. Have you checked plugs, wires, and distributor cap? Also, check output of fuel pump because you could be getting inadequate fuel delivery. Other possibilities are partly plugged fuel injectors, restricted fuel filer and...

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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.