Loud “wehrrrr”

[Jonny]

So today I’ve been pulling some heavy loads and while I’ve been slowly manoeuvring the trailer in either 1st or reverse gear, I’m hearing what sounds like a loud turbo “wehrr”

When I turn the engine off it really makes a noise like I’ve got a turbo the size of a bucket.

Do I have a pipe leak leading up to the turbo ???

 

[Loz]

Mine does this, I brought it up with the master tech at the dealer and he said it’s turdo backspin, if you are blipping the throttle then the pressure created can cause the turbo to spin backwards as it goes back to idle.
I thought it was the turbo failing but he said he has heard it loads of times and its just that the turbo is not really designed to run backwards.

 

[Jonny]

@Loz you are a fountain of knowledge and thank you.

 

[Ads_Essex]

Mine does this, I brought it up with the master tech at the dealer and he said it’s turdo backspin, if you are blipping the throttle then the pressure created can cause the turbo to spin backwards as it goes back to idle.
I thought it was the turbo failing but he said he has heard it loads of times and its just that the turbo is not really designed to run backwards.

@Loz is this the ‘mooo’ sound that people mention or is this something different?

 

[Loz]

@Loz is this the ‘mooo’ sound that people mention or is this something different?

no, not the old N75 moo valve noise.
This is more a chirping spin down sound, its quite difficult to describe..

 

[richi]

Mine does this, I brought it up with the master tech at the dealer and he said it’s turdo backspin.

Sh*t! I bet it goes everywhere

 

[Jonny]

Sh*t! I bet it goes everywhere

Yeah nobody needs that in their life!!!

 

[AndyAK66]

Think mine has the same problem, slow manoeuvring and towing, can the back spin be stopped by the dealership?

 

[Tourershine]

If it's a sound almost like a huge rush of air, or a dump valve, mine always does it when I blip the throttle under load in reverse.

 

[RattyMcClelland]

The turbo makes a dump valve/chatter sound when the engine is regenerating you you apply throttle boost pressure and release the throttle quickly. Usually because of the retarded engine timing.

It's normal.

 

[SofaKing]

The turbo makes a dump valve/chatter sound when the engine is regenerating you you apply throttle boost pressure and release the throttle quickly. Usually because of the retarded engine timing.

It's normal.

At last! I’ve noticed the clatter noise. Never understood where it came from. Its worse during regen, but also under normal running when throttle is pushed. Where is the turbo situated on the t6, 150hp? Should the chatter be constant?

 

[mmi]

Turbo is down at the "back" of the engine (picture of LHD 150PS CXHA), at the end of marked air hose.


My story about similar symptoms was in the post Rattling / clattering / pinging when accelerating

Since then the van has been replaced with a new because of another issue. So no more rattles/clatters any more. Have you compared with a demonstrator?

A thing that didn't mention was that there was also a noticeable judder when slowly (gear 2 or 3 at about 1200-1600 rpm) pulling/speeding up a steep hill). Realized that only after replacement of the van as the pull is now real smooth.

 

[RunDSG]

Mine does this, I brought it up with the master tech at the dealer and he said it’s turdo backspin, if you are blipping the throttle then the pressure created can cause the turbo to spin backwards as it goes back to idle.
I thought it was the turbo failing but he said he has heard it loads of times and its just that the turbo is not really designed to run backwards.

Yes, an old post, but I think this is what my van is doing. I’m trying to work out whether or not I should be concerned.

My van makes this whirring sound when manoeuvring at low speeds and reversing. It sort of throbs or goes up and down about twice per second. And when I shut off the engine, it quite loudly winds down. If I accelerate it goes away.

My local VAG specialist thought it was the turbo and some back pressure. Sounds like a similar explanation to yours.

Is it something to worry about? Can I do anything about it?

Makes my new(ish) van sound old.

 

[Loz]

I don’t notice it much now unless it is doing a regen where it’s quite loud.