I have a 325i 2003 automatic, I hear a loud whistle when I reach around 3rpm and feel a stronger take off, but I cannot seem to find any turbo. Where do i need to be looking

i mean if the car is all stock then there is no turbo, only 3 series with a turbo is an M3, the whistle could be a hole or leak with ur intake....or ive heard that year BMW had some alternator issues with the tensioner

The thing is im not sure if its all stock or not. It, does it as well when im in neutral, if i rev it up to redline as the RPM's jump up and down so does the whistling. I've had the car for over a year now and its always done this.

anything below 3-4ish though and you hear no whistle

http://www.youtube.com/watch?v=vgkcEr64d1s is it like this?

http://www.youtube.com/watch?v=ujWieLXQbgc or this

i would say that is has a turbo on it look around the altonator

the 335 is turbo charged, not the 325, not even the M3 {the newest version might be, but that is still speculation}

Considering the age of the vehicle, you could have a belt tensioner pulley bearing going out. Have you replace them? You could also have a water pump bearing that is starting to fail. It sounds like some routine maintenance may be in order. They go bad around 100K miles.

CJ I'd have to say sounds more like the 1st video exactly the same sound as i take off in the same fashion

hahah ive been looking all over for a solution to this, but seriously, a lot of people have been having the same problem....also no one really seems to know for sure, but all roads lead to it being the air intake, this guy claims to have fixed it: http://www.e46fanatics.com/forum/showthread.php?p=13844661...but it doesnt seem to be a serious problem...i thought it would have been a gasket problem, like a hole around the intake or exhaust manifold

Have you checked your bearings?

I thought the same thing at the same RPM and surprise! Time for pulleys and tensioners. Use a stethoscope or use a long screwdriver to detect vibrations coming from the tensioners.

Its just a cracked intake boot, very common on these cars, definitely not a turbo, as no E46 came with one. The stronger takeoff is just you getting into the power band.