Hey,I currently have a loud tapping noise on my BMW E60 2004. Whenever I accelerate above around 40 km/h, I hear a loud tapping noise coming from the front of the car. The noise is so loud that it's audible inside the car, and with the window open, it's very loud.

Here are some details about the problem:

• The noise appears to come when the engine is hot. For example, during my morning drive to work, it doesn’t occur when I accelerate to highway speeds
• The noise disappears if I ease off the throttle
• It persists even when accelerating above 120 km/h
• The sound is not present when revving the engine in park
• I have already checked the underside, brake lines, heat shields, brake shields and panels, but I haven't found anything loose

Here is a youtube link where the noise can be heard:

Any ideas what can be causing this?
EDIT: The noise seems to come from somewhere in the middle on driver side. The noise only comes when it's really hot outside and the engine is really hot. When outside and engine are hot it sometimes also occurs when coasting.

 

Have you put the car in drive a revved it? Have you put the car in the air then put it in drive and pressed the gas to see if it drivetrain or steering based. At this point I'm thinking it's not the engine

 

I haven't been able to reproduce it in my yard by revving on drive or steering and driving forward/backwards. When I'm driving from work to home, the noise seems to come on the same spot at highway (engine reaches certain temperature at that point?) and after exiting highway and driving about 40-50 km/h it produces the noise intermittently.

Thanks for the tip, I need to jack it in the air and try to find what kind of scenario does the noise when I have the time to do so.

 

To me, it seems like the cycle of the noise (not the "frequency") matches the rotation of the wheels, so I'd suspect a CV axle (or some other anomaly with the rotating portion of the drivetrain). If so, it may (or may not...) change when you're in a sharp(ish) curve at speed.

 

The noise seems to come from the driver side from somewhere in the middle. And it seems to occur only when it's really hot outside and the engine is hot. And outside and engine is hot it sometimes also occurs when coasting.

EDIT: now it seems to come even when it's cold. It seems to come from the middle of the car, like under the center console. Doesn't seem to be the drive shaft middle bearing.

 

You probably need to use a mechanics stethoscope.

 

Apologies for digging up an ageing thread, but I have the same issue. Currently thinking it's a dying injector, but am unsure. Did you get any further?