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Steve, BMW Expert
Category: BMW
Satisfied Customers: 25416
Experience:  BMW Expert
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I have a 2008 X5 bought second hand 3 years ago. I had the

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I have a 2008 X5 bought second hand 3 years ago. I had the battery replaced at my local BMW dealership in February this year, where a diagnostic test was carried out at the same time. Several weeks ago my engine went bang and is currently being anaylised by the same dealership. There was no warning light or any indication that anything was wrong. The car is out of warranty and the bill so far just to find the problem stands at £800.00. Would the computer have automatically been reset after the battery was replaced, if so what could be the reason for the absence of a mechanical warning light. thank you in advance


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.

normally when a battery is replaced at a dealer they update theh computer as this is a required part of battery replacement. the battery replacement is almost certainly unrelated to the current issue, I am not sure why a connection is believed to exist.

a warning light can only be set off by something the car can sense. mechanical failures normally cannot be sensed until some kind of sensor reading goes out of specification in a manner that the car can perceive - this is why no warning light occured, since you likely had a very quick mechanical failure where no system sensed a problem to allow a warning light to be triggered

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

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