When I start my 30 pickup, there are black spots on the driveway , a discharge from the exhaust pipe. It is a mostly dry substance, with no smell, looks like soot from a fireplace. Any thoughts?
Ever started up your modern car and found a puddle of water in an odd spot under the car? It's just a build up of condensation in the exhaust system. Modern cars do it all of the time, in fact the mufflers often have a small weep hole so they can drain. That's all your car is doing, it's spitting out the built up condensation and taking some of the sooting build up with it.