Here's Why BMW’s N63 4.4-liter V8 Engines Fail. Last year, we wrote a story about BMW’s N63 engines being a pain in the butt to run over a certain mileage. Back then, our info came from a BMW April 4, 2021. Tom Harbid. Your BMW X5 won't start because of a problem with the battery, the starter motor, the alternator. If your BMW X5 cranks but won't start, inspect the battery first thing. Then, use jumper cables to get the vehicle started. If your peers didn't start after the jumpstart, you need to tell your vehicle to the nearest BMW issues a service bulletin for models powered by the N63 4.4 liter V8 engine. BMW says “the timing chains on the the N63 have been found to been found to stretch and wear out prematurely Another common problem that triggers a TRANS FAILSAFE warning on a BMW is the low transmission fluid level. When your BMW displays the TRANS FAILSAFE PROG message after it warms up or when you accelerate hard (while pressing the gas pedal to the metal), the RPMs rise, but the car does not move; the problem is possibly low transmission fluid. 118,000 miles. The 2005 X5 BMW V8 has given me all kinds of problems. From replacing engine, transmission, catalytic converter, valve gaskets to fuel injector and ignition problems. The car shuts BMW X5 – (Jan Kliment / Shutterstock) The most common signs of bad O2 sensor in BMW X5 are slow acceleration, loss of power, irregular idling, engine hesitation or jerking when accelerating, high fuel consumption, higher tailpipe emissions, foul odor from exhaust, check engine light illuminates, and sometimes stalling. 1. Damaged head gasket. Your BMW vehicle combines fuel and air to cause the engine to fire properly. This process can be affected by a number of parts, one of such part is the crank position sensor. Also, the head gasket is another part that could possibly cause your BMWs engine to misfire. If you are a DIY mechanic that is replacing the Cam Position Sensor on a 2009 BMW X5 4.8i. Here is your answer. Customer complaint, losing coolant and topping up often we found the leak to be in the gallery underneat the intake manifold. It's mostly connectors that Looks are subjective, but we believe this is the best-looking X5 to date. F15 X5 Engines & Common Problems. Below is an outline of the F15 X5 engines and links to common problems: 35i X5 – N55 3.0L inline 6 turbo X5 35i N55 Common Problems; 50i X5 – N63tu 4.4L V8 twin turbo X5 50i N63 Common Problems; X5M – S63tu 4.4L V8 twin turbo VVgBMQK.