No, it's not optimum. Do you live in a warm climate? Mountains? For some, it is normal.

Although I'm a several-times OM603 owner, most of us don't come here to the gas side, and this question is answered almost weekly in the summer over on the diesel forum. It might be prudent to re-post over there, you can even delete this thread and start over, you'll get a lot more direct experience very quickly there (none of mine have ever run warm).

The radiator can be blocked internally, or failing.
The space between the A/C condensor and radiator is often full of junk at this time/mileage
The fan clutch might be failing
The water pump might be failing (pitted from non M-B coolant)
The head might be failing.

This in addition to your known leak, but the leak is the first thing to cure.

__________________

Gone to the dark side

- Jeff