Bought a 1983 300cd for $300 with 149k. Got the motor running with a primer pump and new fuel lines. It runs strong, but smokes bad. I know the odometers can't be trusted. What would cause excessive smoke?
Valves? Bad fuel? Worn out? air leak in fuel sys?

 

Bad head gasket allowing coolant into the engine? I've heard that's sometimes the cause of excessive white smoke...

Good luck, Mike

 

Both of these have been stated but I want to add.
When I installed a Fuel Injection Pump and the timing was late/retarded I go clouds of white smoke. After advancing the timing it went away.
When I looked it up it said the smoke is white due to atomized but unburned Diesel.

The other is steam from a coolant leak.
Keep an eye on your Coolent level and see if that is dropping.

Prior Owners if they cannot do it themselves seem never to have the Valves Adjusted.

When I got mine it had 198k on what appeared to be the origional Injectors (badly in need of rebuilding).

Another issue could be if you are runing on old Fuel that has been in the Fuel Tank Years and years.

 

Thanks for the info.....Its probably a combo of valves and old fuel. I just got the car and its been sitting a long time.