Whistle in Cabin Under Boost / Load

[vanastasis]

Hi All,

i have noticed under load (boost) i can hear a whistle from the passenger firewall area
I've looked for boost leaks, egr leaks etc.. and can't find anything
could anyone shed some light on my situation please.
could a unclean intake manifold cause such whistle like clogged or butterflies inside jammed
the whistle is only on boost / load ( not high pitch whistle, mid type whistle )
i still have full boost throughout the rev range, no loss of power, no surging and fuel is 7-8l/p 100
2011 NT Platinum DID

[AndrewRe]

I am looking forward to hearing from everyone on this as I have the exact same problem. Had my adult son with a piece of tube to his ear trying to find the spot the noise is coming from. Not sure but it seems worse once motor is warm, but I may be dreaming. Someone here will know.

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[AndrewRe]

BTW I have no EGR, clean manifold, no throttle butterfly, and sound starts to become audible from 6psi and is at full volume by 10 psi and up. Not loud.... Just irritating.

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[PICADOR]

Look for a break intercooler

[AndrewRe]

Thanks Picador
My intercooler is now front mount as the original was tiny and received very little air flow. The whistle was there prior to the upgrade

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[vanastasis]

Thanx for the info, will check intercooler

[AndrewRe]

Thanx for the info, will check intercooler

Have you had any luck?

[Seigried]

Check to see if your intake manifold gasket is leaking.

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[AndrewRe]

Check to see if your intake manifold gasket is leaking.

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This makes sense. Seigried, only issue is proving it without just going ahead and replacing the gasket. Any ideas?

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[Seigried]

If you have a disco fog machine feed it in via the port for the blow by return. Use a bright torch and look for "smoke" leaking out. This will let you check from after the airfilter all the way to the inlet manifold.

I have done this myself after cleaning my manifold. For me it found a leak.

The attached photo show my fog machine hooked up directly to the throtle body using a custom adaptor. After which i tested again by attaching to the blow by return.

Another option is to presurise the system using compressed air. I havent tried that method.

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[Two Emms]

Hmmm, number of forum members with a disco fog machine versus number of forum members with an air compressor

At least with the fog machine, the smallest leak will show.

If you don't have a disco fog machine maybe combine compressed air with a bit of soapy water, just like checking your bbq gas bottle, will make any leaks obvious.

[Xrsteve]

I’m looking forward to hearing what you find.

I have had the same issue since cleaning the manifold. It became apparent during the first drive probably about 10ks in after some heavy boost.

I assumed it blew through a gasket. I haven’t done anything yet as I thought I’d wait till I clean the manifold again and replace the gasket.

I also read on here someone had a similar issue and it was the turbo gasket.

Let me know how you go it might save me some stuffing around.

[AndrewRe]

I definitely will. As a matter of interest. Does your whistle have a vibration in it?
Mine is kinda like the sound made when you hum and whistle at the same time. It's subtle but there. Hopefully I am making sense.[emoji849]

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[Xrsteve]

I’ll get the wife to take a video next drive it’s definitely a boost leak. It’s hard to hear over the 3” but it’s there

[AndrewRe]

I’ll get the wife to take a video next drive it’s definitely a boost leak. It’s hard to hear over the 3” but it’s there

Thanks Steve.

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