Hey everyone. I'm pretty new around this forum. I've had my 1992 300D for about 3 years, and now I'm having some serious issues with it.

Problem #1 (check this link for a thread I started on another forum) http://www.schumanautomotive.com/forums/showthread.php?t=8988 this started about 3 months ago, and got progressively worse ever since. My engine temp would fluctuate a lot. On a hot day it could not even maintain anything below 100*C (normal operating temp is 80*, it goes up to 100* during heavy load periods, such as a hill)
I noticed I was going through a lot of coolant. The engine would get hot, the coolant would expand and overflow out of the.... overflow and then the engine would overheat. I replaced the expansion tank, it's lid, and the thermostat. I believe the tank/lid combo helped retain the coolant for longer, but it would still overflow.

Problem #2 (link) http://www.schumanautomotive.com/forums/showthread.php?t=9162 I go out to start my car one day and.... nothin. The starter will make sound, like it's trying to turn the engine, but to no avail. The engine will not turn over at all, not 1/8 turn. On the other forum some members came to the conclusion that the engine might be hydrolocked and suggested I attempt to turn the engine via crank shaft. I tried that and was able to turn it, not very far due to space, but still, it was pretty easy. Then I went through the trouble of replacing the starter, after that the engine started and ran. YAY! right? No, wrong. We clean up after ourselves, take the car off stands, and wrap up for the day. Next day I try to pull out of the garage and nothing, same symptom as before I replaced the starter. Then I went through the trouble of replacing all the battery cables, having the battery tested, and cleaning the heck out of everything (connections and whatever else I can get my hands on). To no avail. Same symptom.
Then I get back on the crank shaft. It turns a few cm and then... nothing, can't turn it at all, not with two people on it.

Any advice, knowledge, tips, suggestions, ANYTHING!! will be appreciated.

Thanks and Hello,
Ben