My latest discovery in my automatic '84 300D (234ks on the clock) is that when the car is in gear, stationary and on a moderately negative gradient (ie facing downwards on a slightly steep hill), the engine starts to shudder. It's normal gurgle changes rhythm and feels as if it were about it stall. Today this became more apparent than before. I pulled the park brake, slipped it into neutral and reved it till the lights changed which seemed to do the trick. I'd rather not have to do this too much! Any ideas as to what might be causing this?
Thanks in advance.