1990 300E W124 - 103
first 20 miles or so it runs smooth and strong. then it seems that i have to push the gas to keep up the speed and the motor bogs down as if it had an engine brake, like a truck. it goes away when accelerating it also goes away if i floor it and " clean the pipe" after a mile or so of drag racing the engine to about 4500 RPM it runs smooth again. could it be the filter?... i had the vacuum system checked and some tubes replaced. also used high grade fuel system cleaner. using premium gas. i dont drive the car much. it only has 88.900 miles and oilchanges are done regularly....jsut wondering if anyone else has these symptoms....