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Old 02-03-2013, 04:59 PM
01e46sprt 01e46sprt is offline
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Location: New jersey
 
Join Date: Jan 2013
Posts: 28
Mein Auto: 2001 Bmw 325ci sport
I have The same issue on my 01 325. It's your secondary air pump. It runs only when the car is cold to warm the cats. Only runs for about 5 mins than goes away. What's happening is it's become dirty after so long and that's what causes the noise. It's not a big deal if you can deal with the whistle for 5 mins every morning. Atleast that's what my mechanic told lol.
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