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Discussion Starter · #1 ·
Hi guys I've already search for something like that in the research bar didnt find something similar sorry if I started this thread for nothing.

I have some questions concerning some sounds that my passat is doing.

when i accelerate lets say above 1500 rpm or approximately when the turbo kicks in i hear a kind of whistle it seems to come from the intercooler side. And when i release the throttle i hear a tccchhhh like a bov.


2 weeks before i did some changes myself because of a cracked oil pan the engine was on when i had this incident for less than 20 seconds (the oil light was not even on) it turned on for a second before i turned off the engine..
I changed the ol pan so i lifted up the engine a bit and lowered the subframe to do so.
I'm thinking that its related

the intercooler is brand new BTW. What sould i do

Thanks in advance
Nassim
Passat b5.5 Awm
 

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Discussion Starter · #3 ·
thanks for the quick response i fugured that one of my hoses had to be thighten.....and i'll try to do a leak oost test soon.

Does a leak boost give me this BOV sound ?
Is there anyway to clean my Turbocharger ?
 

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Does a boost leak give me this BOV sound?
A leak anywhere in the charge path from the turbo to the throttle body can cause both the whistling sound when in boost and the blow-off sound when you lift off the throttle. Also check your diverter valve to be sure it's functioning and plumbed in tightly.

Is there any way to clean my Turbocharger?
Not really. Is yours excessively dirty? Are we talking about the inside or the outside?
 

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In stock form, the turbo's on these cars are pretty quiet. The air box acts as an intake-muffler and silences the compressor spool noise pretty well. The turbine noise is muffled with the rest of the exhaust noise in the exhaust system. There is no blow off valve like in the movies, but a diverter valve that keeps all that charge air and noise contained in the system. If you listen for it you can hear it spool sometimes but it does not jump out at you. These cars were designed to be somewhat upscale and refined not pavement pounding race cars. An open intake and open exhaust can let out more of the spool sound. Bumping up the boost levels with a tune can also make the sound of the turbo spooling louder.

You should not hear a flutter sound on throttle-lift after boosting. If you do it means your experiencing compressor surge (or compressor stall). The diverter valve is there to prevent this from happening as it's not good for the turbo. Check the function of the DV to be sure it's opening when it should.
 

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Discussion Starter · #11 ·
some news for u guys i changed the dv for the tt DV , cleaned the hoses and i dont have the whistle anymore but i have the sshhhhh which i think is normal since its a better DV, but the thing is that i found some water in the old DV What to do next?

thanks in advance for the reply and advices
 

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If your intake system is stock (not an open cone filter) you should not hear the SSShhh. You have a new diverter valve on there so you know that part is probably functional. Is it getting the vacuum signal to open when it should? If you have a boost gauge, temporarily re-plumb it into the vacuum line that goes to the DV. Go for a quick test drive and see if that line is getting good vacuum when you let off the pedal after accelerating a bit in boost.
 

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It's hard to say without actually seeing/hearing the car. From your description, we're talking about a stock 1.8t AWM that makes a SShhhhh sound when you let off the gas. In stock form, these cars don't make noticeable Fast & Furious sounds. When they do, it's usually because something has been modified or something is malfunctioning. Can you post a video with sound?

A sound like described happens if there is a leak in the charge path or the DV isn't opening when it should. A boost leak test will tell you if you have leaks in the system. You just put on a new DV so that part is likely operational. In order for it to operate it needs to receive a vacuum signal. A vacuum gauge tapped into the DV line will tell you if the DV is getting the proper signal.

Fuel Pump and Vacuum Tester
 

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I tried watching the video and it said "This video is private".

Water in there might possibly indicate it isn't opening. When it opens, a rush of air passes through and would blow that water out. A small amount of oil in any of the intake path hoses isn't unusual.
 
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