hello .
i have mercedez benz SEL500 1993 model with all options...there was no problem in any shift...no noise, i had a car wash from service center at petrol pump...he sprayed diesel on engine and then washed it with water..also from beneath the car...after 5 hrs we were going out we started the car ,,,when we pull gear to reverse ,there was a delay of 7 seconds.but the forward gear is working fine like new...we then changed the transmission oil(original MB) and changed the filter......still the problem last......tel me what should i do..during wash i didnt removed the covers...help me