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CarDoc, Vehicle Technician
Category: BMW
Satisfied Customers: 818
Experience:  IMI L3 Motor Vehicle Mechanic
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My 2008 520D without explanation suddenly just completely

Customer Question

My 2008 520D without explanation suddenly just completely dies. The dash screen goes blank, the speedo sticks at 40 mph, then power steering gets tighter and then it just dies. After that, I jump start it and it's fine. I have had it with an electrical specialist diagnostics guy who cant find a problem. We have tried replacing the altenator, battery but to no avail.
JA: When was the fluid last checked? Have you heard any whining noises while turning the wheel?
Customer: No. Its nothing to do with that. Am I chatting to a bot??
JA: What is the model of your '08 BMW?
Customer: 520 diesel
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: No. with the garage i bought it from. replaced the altenator, battery and had diagnostics carried out but no faults recorded
JA: Anything else you want the Mechanic to know before I connect you?
Customer: No
Submitted: 2 years ago.
Category: BMW
Expert:  CarDoc replied 2 years ago.

Thank you for using JA. I'm Baz, one of the automotive experts, I try to be available in the afternoon on weekdays and in the evenings on the weekend. I apologise if I do not respond to your question promptly, I can assure you that I will respond as soon as I can. Thank you

Expert:  CarDoc replied 2 years ago.

Looking at the symptoms, I would say that it seems like a faulty crank position sensor. But, there are other possibilities such as an intermittent fuel pump failure or the camshaft position sensor. I would put my money on the crank position sensor though.