Well it appears that the old girl may need some attention. We have a 1991, 300e with 198k miles on it and its been a wonderful little car. Over the past several months I've noticed what I think is a valve tap and it is getting increasingly louder. The rest of the car is fine. and in real good shape for the age and mileage. It uses about a quart bt. oil changes but is in good condition and would like to pass it on to our daughter. Can I get some advice on what direction to go in order to determine the problem? Thank you!