2013 — 2018
4.4L Twin-Turbo (N63B44TU) - 650i Coupe/Convertible
Petrol
When idling at a standstill, observe the engine note for any irregular ticking or shaking. | Description: It is common in these V8s to monitor for signs of potential timing chain stretch or injector issues, which can occur as these units age.
Check the iDrive display and toggle through the 'Vehicle Status' menu. | Description: On cars of this age, software glitches or sensor errors can sometimes appear; ensure there are no persistent warning lights hidden in the history.
Operate the roof mechanism (if convertible) or sunroof multiple times during the inspection. | Description: Mechanical seals and motors can naturally wear over time, so you'll want to ensure smooth, quiet operation without hesitation.
Inspect the front and rear differential seals while the car is on a hoist. | Description: Minor oil seepage is something you might eventually encounter, so it is wise to see if the underside looks relatively dry.
Consider a full cooling system inspection and checking the condition of the turbo oil feed lines.
A common point to look at suspension bushings and potential engine mount fatigue.
Look into a transmission service and verification of the high-pressure fuel pump (HPFP) performance.
Prioritize oil changes every 7,500km to keep those turbochargers happy.
Keep a close eye on your coolant levels, as these engines run quite warm.
Ensure the iDrive system has been updated to the latest software version.
Regularly inspect your tyre tread wear to ensure suspension alignment remains true.
Keep records of all service receipts; a well-documented history is a great asset for these cars.
Estimated repair costs if issues arise
Given the heat these engines generate, these lines can become brittle over time. If they need attention, it is a labor-intensive job to ensure everything is sealed correctly.
If the car is fitted with Electronic Damper Control, these components eventually reach their service limit. Budgeting for these ensures the ride quality stays as the engineers intended.
While the facelift engines (N63B44TU) are improved, as the mileage climbs, it is common to consider the potential for valve stem seal wear. It involves significant engine work to address.
Noticed something inaccurate or missing?Suggest an edit→
Disclaimer: This report is generated with the assistance of AI analysis based on verified automotive data. While we strive for 100% accuracy, enthusiasts should always conduct physical inspections and consult service records. View Full Disclaimer