Mechanics

ENGINE TURNS BUT WILL NOT STARTS

2000 Mercedes Benz S500

Engine Performance problem
2000 Mercedes Benz S500 V8 Two Wheel Drive Automatic 139000 miles

Hi my name is Serey and I am looking for some trouble shooting help.

I own a 2000 S500 with 139,000 mile plus. Recently, I took my family on vacation and drove from Mass to Florida and back.

Here is the problem that I'm trying to diagnose.

While I was in Florida this problem occured. I drove the car and stopped to have lunch and the engine would not start. It would just turn and turn and turn. My thought was that there might be an ignition system issue since the engine truns but would not fire-up. So I disconnected the negative battery terminal and I pulled the fuse out one by one to see if I have any blown fuses and after about 10 minutes or so it starts just fine.

It started just fine after that until I got back home and the same problem reoccurred 5 or 6 days later but after 6 or 7 times turning the key it started.

Today (4 days later) I drove my wife and children to visit my parents and now it will not start at all. The engine would just turn and turn and turn but will NOT fire-up.

Any ideas as to what could be the source of this ignition problem?

Any help in determining the source of this problem is greatly appreciated.

Thank you!

Best regards,
Serey V. Oum
Avatar
Mappy0ne
January 10, 2010.



No start condition: Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it

Rasmataz
Jan 10, 2010.
2000 Mercedes Benz S500 Engine Turns but will not starts.

Summary update of the above engine problem.

I returned to pick up my S500 from my mom place and was dreading the worse that I have to have it towed to a repair shop but it was not so. It started just fine.

I bought an OBD code reader and the ONLY codes reported were O2 sensors. I did not want to leave it to chance so I replaced the crankshaft sensor anyway after reading about intermittent engine starting issue and that it could be the crankshaft sensor going bad.

Since then the above problem has not re-occurs therefore one can only conclude that it was the crankshaft sensor.

Tiny
Mappy0ne
Jan 28, 2010.
We appreciate your comeback with the fix thank you

Rasmataz
Jan 28, 2010.