Car jerks at a stop, only when AC is turned on. 2002 v6-3...

Q: Car jerks at a stop, only when AC is turned on.

asked by on November 13, 2017

I've been having this issue for months now. Whenever I come to a stop, whether it be a stop sign or red light, my car jerks and kicks, this ONLY happens when the AC is turned on, I've driven the car with the AC off numerous times and it never has that issue. So far I have replaced the mass air flow sensor, the idle air control valve, PCV valve, the throttle position sensor, and I have also cleaned the throttle body as best I could, none of this has solved my problem.

My car has 118000 miles.
My car has an automatic transmission.

As you may know, the AC system puts an additional strain on the motor. The air conditioning compressor requires torque from the belt system on the engine to power it. When the AC is off, the compressor clutch does not activate, meaning the AC is not straining the engine. When the AC is on, the compressor clutch activates, wherein the drive belt on the engine now turns the compressor which in turn is compressing refrigerant so you can be nice and cold. The Idle Control Actuator is what controls the engine idle. When the AC kicks in, the engine will drop some RPM, and the actuator opens to allow more air into the engine. When you are at speed, the throttle is open from the accelerator pedal under your foot. the Idle control actuator is not active at this time. I would suggest having an exert from YourMechanic come to your location to take a look at the vehicle to verify what may be causing the rough idle.

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

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

What tips should be followed when using the universal garage door opener?

If your car is equipped with a universal garage door opener, it provides you with a convenient way to get into your garage and eliminates the need to carry a handheld remote in your car. However, there are some important...

Car jerks and slows down

Hey there. This may be a sign of a dirty or failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to...

Car won't start - 2002 Saturn SC2

Hey there. When a situation is up and down like this you want to start by taking back to the basics. Take your battery to have it tested. Most automotive parts stores can do this for free. A test can...

Related articles

How to Get Ford Dealership Certified
Ford car dealerships offer automotive technician jobs to mechanics who are certified through either the ASSET or the FACT program.
The Best Used Cars to Buy to Maximize Resale Value
A A car is not an investment. An investment, by definition, increases in value. A car is a necessary purchase, and it will never appreciate in value, with the possible exception of classics and antiques. So, as a used car...
The Best Used Cars to Buy If You're a General Contractor
If If you're a general contractor, you probably aren’t in the market for a used car. More likely, you’re looking for a pickup truck, because you need to haul equipment and supplies to various job sites. Most contractors will likely...