My son was evicted from his home, the owner has placed a lien on his property. He was storing a car for me, title in my name, which I planned to restore. The owner is holding my car, can he place a lien on my auto for my son's debt?

No, but if the auto was stored on his property he can prevent its recovery. Generally you cannot file a lien against personal property. So I'm wondering how you think a lien was applied.

I suspect OP means to say that the landlord is asserting a possessory "landlord's lien" against the automobile. We would have to know the state or country where this is in order to determine whether landord can get away with this.