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Marty
Marty, Mercedes Technician
Category: Mercedes
Satisfied Customers: 53151
Experience:  Bosch Certified Master Tech. Over 35 years experience.
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I start my car its cranking but it wont go through, yes,

Customer Question

i start my car its cranking but it wont go through
JA: Will the headlights turn on? Is the battery fully charged?
Customer: yes , everything ok
JA: What is the model/year of your Mercedes?
Customer: s500.2002
JA: Are you fixing your S500 yourself? What have you tried so far?
Customer: nothing < this was happened 5 times now but when i pushed and wait for 1 hour then start again
JA: Anything else you want the mechanic to know before I connect you?
Customer: thats it
Submitted: 2 months ago.
Category: Mercedes
Expert:  Marty replied 2 months ago.

Hi, welcome to Just Answer. My name is***** problem is most likely caused by a bad crankshaft position sensor. If the car will not start you should test for spark to the spark plugs and test the fuel pressure. If you have no spark to the plugs I would replace the crankshaft position sensor. If you have no fuel pressure when cranking the motor I would suspect a bad fuel pump. The more common problem is a bad crankshaft position sensor, especially if the car would usually start after waiting an hour. The sensor is located at the back of the motor directly behind the left cylinder head.

Let me know if you need anything else. Don't forget to rate my service 5 stars in order for the website to credit me for answering your question.

Marty