Hi....I am new to this forum. Last July,I bought a 1991 350sd [with a motor with about 70k----car has 246k] and have been generally happy with it.

Several months ago as it began to get colder, intermittently it would not start sometimes unless I placed the gear selector on "N". Gradually it has progressed to the point where it rarely cranks up with the gear in "P" and will easily crank with the gear in "N". The glow plugs were all checked last fall and the glow plug light comes on as it should and goes off as it should. We have also kept the block heater plugged in so I do not think it is a glow plug related problem.

Thanks for any advice you can offer.