Hi All
Just want to share some info regarding the diesel air filter on our E53. I recently change my exhaut to a custom 3" exhaust. For some reason after changing exhaust, the black smoke became very evidant even at idle.
I then did some research and found that one of the common cause of black smoke is insufficent air supply hence the there is more fuel to air ratio causing smoke. I then read the service manual and found out that my X5 has never had a air filter service and it has now done 90,000 (2004 model).
Anyway, i thought i gave it a shot and get a local mechanic to change a new pipecross air filter in just to see if that helps to reduce smoke. After the mechanic took apart the air filter componet, he found out that the filter was in a very bad shape. The foam outside had pretty much turned black and the paper filter was all covered in dust. He actually showed me the filter and gave it a few gentle taps and a lot of crap actually just fell out in front of my eyes.
WTF... What were BMW thinking leaving such a important service item so far inside the engine? And why the hell don't they service it.
. The mechanic also mention the the whole air way and the air box itself was filled with crap too.
Service ur filters at least every 30,000ks guys even BMW said you dont have to. Buy your own filter and get a mechanic to change it. It is worth it. The engine now revs more freely and i think i economy will also be much better too plus the black smoke is also gone now.