What could cause a noise like a split turbo hose

What could cause a noise like the noise you get when you have a split turbo charger hose?
I have a very similiar noise at the same time, i.e. underloaded and revving. No noticeable loss in power or black smoke. There isn't a split turbo hose, but something doesn't sound right. Anyone got any ideas?

the intercooler could be causing this or the intake manifold and or gasket ..

i just remembred my 525i made that sort of noise and since there is no turbo it turned out to be the idle pulley bearings for the fan belt

defcrazy said:

the intercooler could be causing this or the intake manifold and or gasket ..

i just remembred my 525i made that sort of noise and since there is no turbo it turned out to be the idle pulley bearings for the fan belt

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The intercooler did show signs of a small leak so I changed it, but it didn't make any difference. I was thinking manifold/gasket next on the list. It only does it accelerating up hill i.e. when you would expect a split turbo hose to make itself known, and I think the sound is coming from that side of the engine, but its a bit hard to be sure from the driver's seat.

The manifold gasket would produce lots of black smoke.

All fixed now. It was the exhaust manifold gasket leaking by no 4 cylinder exhaust port

Richard Martin said:

All fixed now. It was the exhaust manifold gasket leaking by no 4 cylinder exhaust port

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i thought so ..glad your fixed