Just put a britpart breather filter in my freelander td4 but its only temporary till i get the new bmw one. bit of advice folk ive got this whistling noise under my bonnet. Its there when i rev the landy and its there when i engage gear and pull away, usually noise at about 2000revs thought it might of been thrust bearing but noise is there even when not in gear and rev to 2000, sounds like a split hose or something, mechanic can't find fault but said it may be coming from new rear exhaust pipe but i don't agree as it seems to be coming from engine compartment. Any ideas anyone as its doing me head in.