no idea where to start :(

[axgordon]

I did that ball joint on the right side on my 2003 X5. I ended up applying heat with the MAP gas torch in one spot to the carrier, got it hot and then was able to break ball joint loose. I used air chisel from the top to drive it out. Try it. Heat really helps. Don’t worry about heating the carrier with the torch – it is cast iron. Just be careful not to burn CV boot and not to overheat other components. put torch flame on the carrier in one spot, directly outside where ball joint seats. Please use common sense working with the open flame.

[fmugur]

I finally found the problem while being under the car doing the transmission oil/filter change.
The noise was caused by a loose Oxygen sensor. It seems like it was making the noise when the exhaust was getting warmer and it required to be at a certain pressure on the pipe or/and rpms.

[fmugur]

ha-ha-ha... Well the os being loose would not cause the loss of power so...
I had two noises and now I have only one. The wobbly metallic plates noise is gone but there is one more that was covered by the metallic one and it comes with the loss of power.
So problem not solved yet...

[SlickGT1]

So which noise remains?

[fmugur]

I cannot describe well. I hear something like gears/sprockets. I will pay attention on my way home tonight and have more descriptive words. I hope it's not the transmission.
I changed the oil and filter and there was nothing unusual, all clean but the oil darker as expected for 220k km.
It is hard because I only hear it when driving around 20-40 km/h under load, suspecting only the right side. It doesn't happen if I don't accelerate.
I have to drive along a wall to get the sound reflection from under the car for a clearer sound...

[bcredliner]

Originally Posted by fmugur

I cannot describe well. I hear something like gears/sprockets. I will pay attention on my way home tonight and have more descriptive words. I hope it's not the transmission.
I changed the oil and filter and there was nothing unusual, all clean but the oil darker as expected for 220k km.
It is hard because I only hear it when driving around 20-40 km/h under load, suspecting only the right side. It doesn't happen if I don't accelerate.
I have to drive along a wall to get the sound reflection from under the car for a clearer sound...

Is the sound and power loss intermittent or does it happen every time in the above circumstances? How much load, pedal to the metal? Is it a huge power loss?

[fmugur]

Yeah, it feels like I am driving a 3L not a 4.8is at that time. Regular driving load, not excessive to generate the problem. The more I press the gas pedal the louder the noise is.

[bcredliner]

What does it sound like? The loss of power stops after reaching 40?

[fmugur]

OK. Some update. Since I couldn't locate or describe the noise even, I took the car to a mechanic. Based on his findings it seems to be the resonator that creates the noise. Really? He said that the resonator is smashed at the bottom and the plates inside are most likely bent and loose as well and that's what's causing the noise. Would the power loss be an effect of a bad resonator?

[bcredliner]

Could be if the exhaust flow has been restricted more that normal. In that case a power loss would increase as the exhaust pressure increases, that would directly correlate to increases in engine rpms.