Engine Acceleration reduces with a mild hissing sound from engine bay

[Henn28]

Definitely need to check the codes and live data looking for anomalies. The sound you are hearing (hisssing) doesn’t match anything similar from my 4.6 motor, but I will say the power from my engine comes on with a very noticeable “bang” around 3500 rpm. It pulls strongly before that, but really rips at and above that approximate rpm. So the hissss and power surge may be somewhat unrelated. I do have a mild tune running on my car, but other 4.6 owners tell me theirs is biased to higher rpm.p too.

Have you done a detailed visual check of the vacuum and intake plumbing? I was having odd issues with my e53 early in its new life (2002) which turned out to be the intake boot which had (very) partially slipped off the throttle. The cars are also very particular about the vacuum plumbing integrity it seems.

[farhanbd]

Originally Posted by Henn28

Definitely need to check the codes and live data looking for anomalies. The sound you are hearing (hisssing) doesn’t match anything similar from my 4.6 motor, but I will say the power from my engine comes on with a very noticeable “bang” around 3500 rpm. It pulls strongly before that, but really rips at and above that approximate rpm. So the hissss and power surge may be somewhat unrelated. I do have a mild tune running on my car, but other 4.6 owners tell me theirs is biased to higher rpm.p too.

Have you done a detailed visual check of the vacuum and intake plumbing? I was having odd issues with my e53 early in its new life (2002) which turned out to be the intake boot which had (very) partially slipped off the throttle. The cars are also very particular about the vacuum plumbing integrity it seems.

Dear Henn28, thank you very much for the response.

I am fully aware of the fact that the vehicle is designed as such that it rips at and above 3500 RPM and I used to love it! I am fully aware of this vehicle’s natural instincts as my family has owned this vehicle since brand new.

But, wherein at about 3500 RPM the vehicle used to level up its acceleration in a steady, confident, smooth fashion, these days it actually hesitates between 3000 and 4000 RPM and then after 4000 RPM it opens up abruptly as if it was let go of its leash.

I actually have not checked the intake boot and nor have i checked the vacuum system. Any further specific guidelines on both of these aspects will be greatly appreciated.

In the meantime, the updated fault codes are as follows:

000001
000002
00000A
000014
00001D
00003C
000062
00008C
00008D - DME: Activation, electric fan
00008D - IKE: EGS signal line disturbed
000090