2001 Mercedes Benz C270 Two Wheel Drive Automatic 212000 miles
System starts up normally, engine starts very easily but starter pinion tries to re-engage for about 2 seconds after engine starts. Checked solenoid lead with relay removed - ECU opens circuit after 5 seconds so cranking protection works. Same test on normal start shows bright test lamp until engine starts but flickers and dims for a further 2 secs before circuit finally opens. (I thought this circuit should open once the key is released?). Horrible gnashing sound during those 2 seconds but stops immediately when test lamp goes out. NB - system is one-touch start i.E. Starter solenoid pulls in on ignition circuit but is held in by starter motor current until pinion is pushed out on helical splines and motor circuit through solenoid is opened. Any ideas?