W140 heater not hot enough
 

I have to set the temp to above 85 (max) before I get any heat out of the vents. Is this normal for a W140? Shouldn't it start getting warm when set at 75 or higher like my other cars? I am worried with winter coming in a few months. Any advice from anyone is appreciated. Even at 83 no heat comes out of the vents with the engine all warmed up runnin on the freeway.

thanks in advance

I had the same problem....it turned out to be
 

a stuck thermostat. Yours might also be a coolant valve though.

Good luck..