...when idling. Car also shakes For the past two weeks, after starting my car, shakes and hesitates while idling. When I accelerate, it hesitates and jumps quickly into the next gear. When sitting at a traffic light, I noticed that when it hesitates, the rpm and the battery needles go up and down a bit. When the light panels are on they dim when it hesitates. If the heater is on high the blower slows down. What could it be? I had a series of replacements done in the past two months: new radiator, new water hoses[upper and bottom], manifold, oil change. After i had the hoses placed on my car started up with this problem.