with my eldorado and it?s elc(electronic level control),when i turn the key to on i hear it running but i don?t notice any movement in the car. when i have two adults in the back the elc runs for a long time and when driving, the back of the car will rub the tires over light to medium bumps. i?m thinking this is not normal. does the elc work when ever the car is on or just when i start? should i have it checked for a leak?