Hello bought a 04 Sl with 177K from the auction. I haven't done any maintenance yet but had no problems until recently when it would shut off after extended idling (over 1 hr) but it would restart after extended cranking. Then sometimes the cold engine would require extended cranking to start and now it will shut off while driving and restart after pulling over and turning ignition off then back to start. Where should I start with diagnosing?


Thanks

 

do you have a CEL? could be a crank/cam sensor issue

 

hook a obd reader up to it to see if any codes are stored in there. the hard starts sound like one of the camshaft sensors.