Just one more point I think would be real important- whether or not you tow the car home immediately. When you take the glow plugs out as in the procedure above, try to crank the engine over by hand to make sure it is not seized up. If it's a manual tranny, put it in gear and rock the car- if you see the pulleys turning you're OK. If it's automatic, try getting a big socket and breaker bar on the crank pulley and see if it budges. If it doesn't budge, liberally shoot some good penetrating oil into the plug holes and let it sit a few hours, then repeat this procedure. It may come unstuck, then you can try cranking it with the starter.

Dave

1976 300D