Strange noise from intake system on 1.8TQ


Registered User
Jun 5, 2004
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I recently started to hear a strange sound like a 'chattering/rattling' sound from under the engine. I traced the noise to the airbox initially when I removed the top rectangular intake section. Having removed the filter and taken off the intake hose leading to the turbo the sound seems to be coming from the intake hose.

Does anyone have some advice as to what this could be. Could the exhaust cause noise to travel up the intake system or is something mechanical on the way out??

Thanks in advance of any help/advice.
Another thought is could this be noise from the turbo? I have heard of 'turbo-chatter' on some cars and also noisy bearings on the turbo requiring a replacement.
sounds mechanical, sounds like the turbo, hopefully it doesnt sound expensive :)
I lost & found and found (3 weeks) later a screwdriver in my intake pipe just after the MAF sensor.

Sounds a bit daft but check there is nothing like that in there. Maybe left when you/someone has been working on it.
Well this gets more interesting. My misses has a 1.8t (163bhp model)cabriolet and i listened to the engine running on that and heard what sounded the same noise. Took the rectangular hose section off the airbox and it is exactly the same noise. This is either a common normal sound or we are very unlucky. Her car has only done 26.000 miles. Mine has done 47,000.
Sounds like either the secondary air pump or the evap canister solenoid chattering, either way perfectly normal and nothing to worry about.
Does the noise only occur at certain revs?

Does it get louder with revs?

Can you hear it at idle?

If you can't hear it at idle then i'd suggest it's boost related and the most common thing to break in that area is the diverter valve. If the diaphram splits it will leak boost at higher revs this sounds like a fluttering/chattering noise.