Sitting In My Car With Engine On. Running on battery 1/2 charged waiting for my mom with the heater on. Turn out the heater all the way to max so the engine comes on. To charge the battery. It sounded bad like to starting over and over for 10 sec. then I turned down the heat and back up worked fine. It done some thing like this at lights too. Running ruff then other time it fine Have new plug and battery, air filter and ran cleaner throw gas….
1. Check if the throttle body needs cleaning. 2. It's a pain, but replace the PCV valve. 3. You may have an intermittent plug igniter (separate coil per plug) or loose ignition wiring. Good luck, JeffD
If the 3rd scenario was true, you will also see the CEL light up and possibly the word Problem and a warning icon pop up on the MFD indicating a P030x DTC is triggered, which means a misfire has occured.
By The Way, you don't have to do anything to manage battery charge. With the car on ("Ready") and in Park the engine will start automatically when it needs charging. If you make the engine start by turning up the cabin heat when you don't really want cabin heat, you're just wasting gas.