2005 F/L 3.0diesel hissing

[The Diesel Guy]

Originally Posted by powers1

The 3.0D engine has a a weak exhaust manifold which can lead to cracking if you EGTs(exhaust gas temperatures get too high).With a re-mapped car,this is aggravated,unfortunately!

Get your head under the bonnet ,next to the turbo side and get someone else to rev the car ,and see if you can hear the hissing or smell exhaust gases.

If the hissing isnt the exhaust,it be could be the turbo hissing/whistling.

Hissing noise can also be a very small vaccum leak which isnt yet affecting performance very much .

BMW have looked at if briefly and think it's something else. One thing I forgot to add is that under hard acceleration the noise almost dissapears, but normal acceleration it is most audible.

[powers1]

Originally Posted by The Diesel Guy

BMW have looked at if briefly and think it's something else. One thing I forgot to add is that under hard acceleration the noise almost dissapears, but normal acceleration it is most audible.

So what do "Bmw" think it is,then?..They completely put aside all my previous suggestions?

I am a bit confused now ,when you say that noise almost disappears under hard acceleration,when on your opening post ,you said this,... "it appears to sound like an exhaust leak at idle and then under any acceleration (gets louder with more pedal) is a very loud hissing noise like air or boost is escaping"

Trying to help you ,mate ,but difficult when you being contradictive!
Keeps us posted to what "Bmw " say, please