My 84 533i 5spd (148k) is experiencing a wierd sort of pulse or heartbeat through the brake pedal. When I come to a complete stop and I leave my foot on the brake pedal I can feel and hear a pulse. The pulse quickens when I'm stuck in traffic for a long time. However, if I take my foot off of the brake pedal the pulse goes away. My car seems to brake fine though. My idle is running slightly high too. I'm not sure if this is a related problem or not. Has anyone experienced this before??