andy007

Might be me, but I'm sure the turbo whistle is louder than normal, it is hotter here in UK today. I removed the dpf filter ages ago, so you do notice the whistle, but just seems louder, still lots of power and going ok.

olliecampbell

I believe removing the DPF will make it a bit louder. Otherwise....leaking exhaust/turbo gasket somewhere? Or dying turbo I guess as a worst case scenario....

0xhubey

I find my 2006 525d FSH has a slight whistle/whine under heavy acceleration between 1.5-2k. Almost sounds like a slight air leak (as far as I know I’ve just came from an NA petrol so may be wrong) so I’m assuming there may be a small pinhole somewhere. No loss of power, no smoke and no errors on dash. Am I being daft or is this totally normal?

andy007

Guess what, found out someone tried to steal my dpf filter, left the cover plate off and undone the exhaust, they must have been so p...d off seeing it already missing, i had a deleted, unlucky dick heads.