Funny sound and vibration at acceleration
91 300SEL. From time to time (not all the time) when I need to accelerate quickly from a stop I feel a vibration through the accelerator pedal and hear a clanking sound under the car. It sounds like something might be grinding or loose. The sound will stop when I left off the pedal and then resume acceleration. The sound seems to be comming from between the front axle and firewall areas under the car.