I have a 2001 SL with 79,000 miles on it. For the past 30,000 miles, when the car is first started in the morning, it makes a dry running noise, like a heavy swishing for about 1 second. I have started using STP oil treatment, and it has gone away. but I tried going back to just normal motor oil, and it appears again. Which leaves me to believe it is running dry on startup for some reason. Does anyone else hear this noise? It is quite loud and noticable. I have tried different types of oil filters to see if that is the problem, but no luck.
