Okay, got the 75C thermostat yesterday, will do what I gotta do by the end of the week. Worse comes to worse, I have an appointment with the independant MB mechanic near here on the 6th, so I have plenty of time to track it down.

Will also try the burping, ctaylor738, and let you know. Been busy with work interrupting my auto work. I am sure you can understand. Will keep you posted.