My 79 300sd has been real hard to start this winter and was hoping to get some ideas on things to check.
I replaced the glow plugs about a year ago- did not notice a difference.
new NAPA battery 4 mo. ago.

I turned the key to the glow plug on position a couple times and did not feel any heat (with the plugs in the block )-----is there a way to test this?

The starter motor seems to loose the flywheel .. I have to bring the key back to the off position because it just will sound like a motor running----bad starter?
I have to retry about 5-10 every morning, evenings are not usually a problem. Starts like a champ when its warm (driven in the past 2-3 hours).

can this cause damage to the flywheel?

Also puts out a nice cloud of smoke when it does start which takes about 5 min from 1st attempt to running.
Thanks in advance