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Steve, BMW Expert
Category: BMW
Satisfied Customers: 25242
Experience:  BMW Expert
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I have a bmw e38 728i with 136.6k on the clock on a

Customer Question

I have a bmw e38 728i with 136.6k on the clock on a 97 plate. I took it for a service and MOT as it seemed low on power. On the drive back home, the car seemed nice and smooth but after about 30 miles once it had warmed up it seemed to lack power sounded and felt awful. The following morning, when I started it up from cold it felt and performed well. I spoke to the garage and they said that they had replaced the crank sensor with a non oem which was almost a quarter of the price as I was in a hurry to get the car back.
Again, I drove it to the garage this morning, about 60 miles away, and it felt fine all the way. They read the code on it and it came up with the crank sensor but not lights on the dash. They cleared the code and then we disconnected the battery and then shorted the battery leads to clear the memory. The car was fine. Then later in the afternoon, on the long drive back home, again the same thing all of a sudden a loss of power and it sounded and felt awful.
Any ideas as to what it could be??
Submitted: 2 years ago.
Category: BMW
Expert:  Steve replied 2 years ago.
I will provide an honest answer. I trust this will be appreciated. Please remember that a low rating PUNISHES me for being honest and that I receive nothing for my time until a positive rating is clicked.
This could be an issue related to non oem parts so I would put back the original crank sensor or a new oem one.
Other than this, could be a fuel pressure error, bad spark plugs / coil, or temperature / airflow sensor issue.
Please let me know if you have further questions. Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you. Best wishes with your vehicle.