I have a 1981 300D that runs great. I even had a mercedes master mechanic tell me for the miles,174k, that its the best he has driven. When we got our cold snap, single digits, the car had a real hard time starting. It was expected. For some strange reason I popped the hood and took off the crankcase vent into the air cleaner. Turned the key and started right up. It has worked 3 times now. Why? Dosen't make sense to me. Maybe I shouldn't question success.