I have an 06 WK 5.7. Every time I stop at a light with the A/C on, my vehicle will rest at around 600 RPM and after 5-25 seconds it will drop to 500 RPM for a second and then pick itself back up to 600 RPM again. At 500 RPM, the engine sounds like it's struggling (it sounds similar to an engine running bad fuel) and will vibrate the vehicle. I had this happen a couple of times in my previous vehicles, but it never happened as often as it happens in my WK. Is there anything I can do that will prevent the engine from doing this besides turning my A/C off or not stopping for traffic signals
? Thanks in advance for the help.