Car runs fine with A/C off. When I turn the A/C on the car has a noticable vibration especially idling. No Engine mods or tuning. Engine is Stock. 2009 SS/TC

 

Check ur mounts

 

My car has always done this...stock and with solid mounts.

Must be a cobalt thing

 

all the stuff is belt driven right? power has to be taken to power the ac so the alternator maybe will affect the idle

^if what i said makes no sense well power has to be moved around, no ac all power is there


cobalt thing....for life

 

must be a cobalt thing cause mine always did this since one

 

Yeah its because the car lugs itself at idle when the ac is on. The AC adds a load to the engine. Like 100 more RPM and it wouldnt do that. but its all about fuel economy im sure!

 

Mine's always done that too, seems normal for a small, cheaply built 4 cylinder.

 

AHHHH ANSWERS FINALLY!!!I wanted to kill someone because I couldn't understand why this would happen -.-

 

If you're tuned it could be in your tune have to mess with idle timing and airload, it should fix your issue