Duke:

Thanks for the reply.

I went back thru my notes. Whenever I do a project like this I write down start times, how long 'til upper hose starts getting hot, etc. etc. I monitor the process form start to finish.

The car idled for 40 mins. The temp gauge was at max and as the temp gauge rose, the heater started putting out a good amount of heat, leading me to believe the coolant had gone "full circle". On a lot of cars, a sure sign of an air lock is no heat, quickly following by a rapidly accelerating temp gauge. This never happened.

MBDoc once wrote(I haven't been able to find the thread) that on a certain model of car that had the 103 motor, elevating the front was needed to bleed the air out of the cooling system.

If I have air in the system, why are my operating temps good -> no more than 82C-83C?

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"