BMW Z4 Differential oil is contaminated Inspection at your home or office.

How it's done:

When the mechanic arrives, he or she will raise the vehicle and inspect the differential for any leaks or superficial damage. In order to remove the contaminated oil, the mechanic must drain it from the differential.

If the mechanic suspects that the oil is old, he or she will drain the oil and inspect it to see if there are any metal filings that may have damaged the gears in the differential. Depending on the amount of metal shavings in the oil, the mechanic may want to inspect the gears for damage. The mechanic should then plug the differential and refill it will clean oil.

If the mechanic suspects that there may be water in the differential oil, he or she will begin by draining the contaminated oil. Oil with water in it typically looks gray and cloudy. The mechanic will then replace the contaminated oil with fresh oil. He or she may also drain some fresh oil again to make sure all of the water has been removed from the differential

In the case of all repairs, the mechanic will make sure that he or she replaces the contaminated oil with fresh oil before leaving. The mechanic should also start the vehicle and inspect the differential to ensure that there are no new leaks.