Sahil

My car has done 25,000kms and I have been noticing a gradual increase in the diesel engine sound. I even compared it to an E280 CDi and found that my 525d was much louder at idle.
When standing in front of the car facing the kidney grill, the clattering of the engine is pretty loud moreover when the engine is warm with the AC on makes the sound louder.
My car is due for service soon, what measures should I ask the service guys to take so that the sound increases. Any methods of better insulation options?

Also, since my car is LCI with exhausts pipes bent, i believe it has no particle filter? Is there any other way to reduce the black smoke under hard acceleration? I have already had an turbo assembly change in the past as they claimed oil leaked into it and caused the smoke.

nudda

ive got a 2005 525d and i dont think its too loud. once the engines warm, i find it doesnt make much noise. Also no smoke from behind (none that ive noticed!)

Phantom Mark

Whats the quality of the fuel like in India ?? Just a very wild guess here but if the fuel is not great quality it could cause the problems your talking about..........

If you had oil leaking into your turbo previously I would hope they also changed your crankcase breather, as that was the likely cause in the first place, if they didn't then maybe its done the same again !

Sahil

Fuel quality is not that good in India. But impurities usually get thrown out in black smoke, do they also cause the engine to become noisier?
The fuel quality has been the same since the start but the increase in sound has happened over the past few thousand kms.
I think the crankcase breather was replaced but will double check.

Phantom Mark

The build up in crap in your engine due to "rough" fuel may have caused an exaggeration in the symtoms ??

Yes, a noiser engine is possible on low grade fuel - I think they call it "knocking" when low grade fuel is used.