Last week I was doing about an hour or more of urban, stop and go driving. Ambient temperature was about 85F+/30C+, which probably made the radiant heat off the pavement even hotter.
While my radiator/indicated temp was fine (above 180 but below the line before the red line, and holding steady) the auto transmission behaved erraticly. For example, on some occasions, when accelerating from a stop light (hence the stop and go...) it seemed that the engine RPM was going up, the car was going nowhere, and then all of a sudden it kicked in with a chirp of the tires. In this case it seems like the fluid/torque converter wasn't passing the power. Other times, the shift points seemed all wrong. Clearly the auto trans was not happy.
I try to avoid this stop and go in the heat--aside from the car it isn't comfortable for the driver! But when I do, I'm curious as to whether this is an idiosyncracy of the transmission or some issue yet to be solved? In normal driving (not extended stop and go)and in cooler weather I don't seem to notice anything amiss.
N.B. Factory rebuilt less then 10,000 miles ago; just had a fluid and filter change, and it has done it in the past, too.
Ideas?
Michael Salemi
1969 280SL
Signal Red 568G w/Black Leather (Restored)
President, International Stars Section
Mercedes-Benz Club of America