if your indy has the correct tool for checking pressure on a kjet system, then he can do the benz. kjet is not benz specific, but it was euro only for a long time in the 70s-audi, vw, saab, volvo, bmw mb, etc and into the 90s with benz and ferrari. if he can't, find someone who can. otherwise it will get real exspensive when things replaced don't fix the car. and kjet stuff is high enough already. spend the money on diagnosis, it'll be cheaper in the long run. good luck, chuck.