I'm a diesel novice, but have had lots of old gasoline fueled cars, from 1930's - 1960's. Have had my 300cd for about a year and driven about 7,000 miles. Adjusted 300cd's valves last week (all were a little tight, but ok and was last done about 9,000 miles ago according to records). Replaced glow plugs last year. Had in-tank fuel screen cleaned last year. Now about 1/2 way through a tank of fuel that's about a week old. Started this winter even at 20 degree temp all day. Car now in heated garage. Has been starting and running ok. Driven several times previous day without a glitch. Nothing unusual -- until yesterday morning. In heated garage, turned key and glow plug pre-heat light worked normal. When pre-heat light went out, engine did not start. Battery working fine. Guessing my only choices are lack of fuel or somehow glow plugs not working. Help!