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Strange Sound When Coming Off Boost

ChrisB

By ChrisB,
in Four Door Family & Wagoneers

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ChrisB Rising Star

ChrisB

Posted
Posted

As the Stagea is still new to me and I'm just getting used to it, I hope i can be forgiven for asking some stupid questions.

A few times now I have noticed that if I give it a bit of a squirt the Turbo whistles nicely and everything is happy, then just as I lift my right foot I sometimes here a strange sound. I wondered if it was just the normal sound of the pressure being released? It doesn't happen every time which got me thinking that it wasn't normal.

How does the VQ25DET normally sound with a stock turbo and stock exhaust when dumping pressure?

OK so it's a bit of a stupid question without a sound clip to explain it better i know.

Usually the turbo is just on from 2000 rpm all the way and whistles away nicely all day during normal driving so i think its OK.

Maybe we should start a whole thread with sound recordings for your listening pleasure. :whistling:

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scotty nm35 Grand Master

scotty nm35

Posted
Posted

Any weird noises should be checked out, the stock turbo would have been nearly silent when new. I have a good one here that barely makes any noise. I will check it out on Saturday, it may pay to search for the "cleaning the banjo bolt" threads as lack of oil supply would be one of the major factors in turbo failure imo.

HER_M35 Enthusiast

HER_M35

Posted
Posted

Hi Chris,

Have a look at the threads where "Farting BOV" is mentioned.

The stock BOV can begin to fail sometimes, causing this sound which is almost like a shudder through the car at times.

You'll notice it gets worse over time too.

There's a few solutions; you can go OEM/Stock Bypass Valve from Nissan or a direct aftermarket replacement with the Turbosmart Dual Port (part number TS-0205-1026) and i'm sure there are a few others too.

I ended up going for the Turbosmart option and i think a few others on here have too. Fixed the problem immediately, direct fit and really no adjustment required initially, just bolt on.

One thing to note though, even in full plumb back mode the Turbosmart can sill be heard releasing the pressure but it's a standard BOV sound and not a fart!

Hope that helps mate,

Jas

ChrisB Rising Star

ChrisB

Posted
  • Author
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Crikey you guys are good!!!

Yes it sounds like a fart an it can make the car shudder.

Also transmission crossed my mind as it can do it through boost when it shifts gear.

I couldn't get the car to do it today as it is intermittent.

Is this an expensive part? Warranty item from the dealer under statutory warranty or not worth the hassle?

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Perhaps do the coke can under the BOV trick and see if the noise goes away. Or drop in and I can quickly tap a thread into the BOV bypass hole and see if it helps. Its a fairly simple valve at the end of the day.

ChrisB Rising Star

ChrisB

Posted
  • Author
Posted

Perhaps do the coke can under the BOV trick and see if the noise goes away. Or drop in and I can quickly tap a thread into the BOV bypass hole and see if it helps. Its a fairly simple valve at the end of the day.

Scotty, your unreal. Hopefully see you Saturday and we can make a plan then.

Cheers

ChrisB Rising Star

ChrisB

Posted
  • Author
Posted

Perhaps do the coke can under the BOV trick and see if the noise goes away. Or drop in and I can quickly tap a thread into the BOV bypass hole and see if it helps. Its a fairly simple valve at the end of the day.

Scott, just noticed that Saturdays cruise has been postponed.

When and where would i pop in to? PM me if you like.

Thanks

Chris

HER_M35 Enthusiast

HER_M35

Posted
Posted

Crikey you guys are good!!!

Yes it sounds like a fart an it can make the car shudder.

Also transmission crossed my mind as it can do it through boost when it shifts gear.

I couldn't get the car to do it today as it is intermittent.

Is this an expensive part? Warranty item from the dealer under statutory warranty or not worth the hassle?

Sounds exactly like the problem Chris.

I'd try as Scott suggested to ensure it is the problem before shelling out coin on the problem.

If you do need to get one, i can recommend Boostn Imports www.boostnimports.com , Paid $387 delivered, Mick is great to deal with.

I think they might be a Trader on SAU too?

Jas

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