Okay, so it's been very, very cold in VA over the weekend and in the single digits once or twice at night. I attempted to start my 84' 300SD in the morning, turned over once or twice then...nothing battery completely dead. I Called the mercedes roadside assistance for a jump, he showed up, attempted to charge my Sears Diehard battery (which was a piece of junk to begin with) and it took 18 minutes showing very little charge. So fine, I had enough and asked the fella' to replace the battery with the new mercedes battery he had. Boom! 4 minutes later car started right up. Next he recommended that I put some karosine/gasoline in the car to keep the diesel from geling overnight, hence I put in one gallon. I drove the car for a few minutes and next I start hearing these random clanking and pinging sounds from underneath the hood. In dispair, I'm thinking ohh' Lord no!! What have I done? I drive home park the car and wait for a few hours. Midnight, I decided maybe I should top off the tank with more diesel and purchase an additive in case some unknown problem should arise. The pinging persists almost embarrsassingly so at the stop light. The next moment, the pinging and clanking stops all the while the car is excellerating, and running smooth even at idle, but as the pinging and clanking stops....all of a sudden the dashlights come on, GAS, BATTERY, SEATBELT and the steering gets tough....WHAT IN THE WORLD JUST HAPPENED? Can someone please help..Is this due to the gas, the new battery, a dead or weak starter or alternator..camshaft pulley? Any ideas?