How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Marty Your Own Question
Marty, Bosch Certified Master Technician
Category: Car
Satisfied Customers: 54950
Experience:  Bosch Certified Master Technician with over 35 years experience in the automotive industry.
Type Your Car Question Here...
Marty is online now

Mercedes c230k 2001 Occasional sudden engine cutout when driving

This answer was rated:

Mercedes c230k 2001
Occasional sudden engine cutout when driving - problem looked at but not resolved
Any clues?
restarts if travelling fast but slowing down or at lights it stalls
Frequency of occurrence: once in every hour of travel (roughly)
Hi, my name isXXXXX you know exactly which part was replaced for this problem?
Customer: replied 4 years ago.

yes the engine sensor -

Ok, could you mean the crankshaft position sensor?
Customer: replied 4 years ago.

Yes I expect so.

Ok, does the car turn off suddenly as if the key was turned off or does it gradually die as if it were running out of gas? Does the car restart immediately or do you have to wait a few minutes before it will restart? Also, are the symptoms exactly the same since the sensor was replaced?
Customer: replied 4 years ago.

Sudden switch off. Starts quite promptly since we also had a fuel leak

repair carried out a couple of months ago.

(sorry for delAY IN REPLYING got cut off)

Customer: replied 4 years ago.

sudden cutout Satisfactory restart fairly promptly


Ok, to be honest with you this sounds most like a faulty crankshaft position sensor. The sensor is notorious for intermittently cutting out and causing sudden stalling. If an aftermarket crankshaft position sensor was installed I would be even more suspicious of the sensor intermittently cutting out. Other problems that can give a similar symptom are a faulty fuel pump or fuel pump relay or ignition switch but the crankshaft sensor is the number one cause of this type of symptom. I would check to see which sensor was replaced and whether it was a genuine Mercedes sensor or an aftermarket type. I'd also get the car connected to a Mercedes scan tool to see if there are any fault codes stored that point to the problem. Often when the crank sensor fails intermittently it does not leave any fault codes. Replacing the crankshaft sensor with a genuine Mercedes sensor would be my advice.

Let me know if you have any questions.

Marty and other Car Specialists are ready to help you