Noise at 1350rpm

[Kallaskalle]

New video i recorded today, the gas pedal is fixed to around 1300rpm with a stick.
The engine is doing the pumping.

Very clear it’s from the intake side, the sound is very much noticeable from the air filter box.

I notice a burnt rubber/plastic smell from the exhaust when the issue is present (almost every time I drive now)

The start/stopp function doesn’t work any more, no problem for me but someone asked about this earlier in the thread.

 

[Phill09]

New video i recorded today, the gas pedal is fixed to around 1300rpm with a stick.
The engine is doing the pumping.

Very clear it’s from the intake side, the sound is very much noticeable from the air filter box.

I notice a burnt rubber/plastic smell from the exhaust when the issue is present (almost every time I drive now)

The start/stopp function doesn’t work any more, no problem for me but someone asked about this earlier in the thread.

Did you manage to find anything? My T6 140bhp is doing the same now ‍

 

[Kallaskalle]

Nope! The noise is still present and the car is still running without any breakdown. Bad mileage when noise is present, restart engine and it’s gone, and mileage returns to normal.

almost every time I drive ≈10km the noise appears.

 

[Kallaskalle]

It’s Very cold where i live now, and the engine have a hard time getting warm. I get no noise as long as the engine is cold, by cold I mean under regular working temperature (80-90 C/170-195 F). Just adding a clue to the mystery

 

[temporarysecretary]

Sounds like tensioner belt related to my ears. I'd pop the cover off the belts on the side of the engine and see if the tensioner is releasing tension when the noise happens.

If that is inconclusive I'd pop the air intake off the air box for a moment and see if you hear the sound coming out of the air intake more than you do the engine bay. Just be careful to not get anything in it. You will know straight away as it will be a fair amount louder.

 

[kirkm5238]

Hello guys anyone get to bottom of this noise my t6 140 dose the same thanks

 

[Kallaskalle]

Nope the sound is still present on mine and almost every time I drive.

Noticed that the car been drinking about 1L oil since the change last year (around 2000km/1200miles). Had to top it up last week. The exhaust smells weird/burned when the issue is around. Bad mileage, feels little weak and slow. And some times I drive it’s feels perfect, good mileage, spins like a cat in the engine.

 

[The Bear78]

Hello guys anyone get to bottom of this noise my t6 140 dose the same thanks

Mine did it when I bought it 5 years and 50000 miles ago. Mines a 140 too.
'Still does it now...
It's only on a light throttle, never under load and not all the time.
Since buying the van I've had the belts and pulleys changed and replaced the egr assembly (for other reasons) but neither made any difference to this noise.

 

[Kallaskalle]

Got my car back from drifshaft/dsg diff failure and have also changed the cam belt and water pump so we can take that of the list at least

But now when I put a lot of money on it with that rapair and service the sound irritated me a little extra today when the sound appeared.

I plugged the cable for the air mass sensor out when car was running and the wierd sound disappeared.

I bought a new sensor a couple of years ago when I got a fault code on it, p0101 or something and the fault code has not appeared again so I took for granted that the new sensor was good and didn’t cause the sound. But maybe it’s something wrong with it or something regarding air mixing?

 

[Stefan]

New video i recorded today, the gas pedal is fixed to around 1300rpm with a stick.
The engine is doing the pumping.

Very clear it’s from the intake side, the sound is very much noticeable from the air filter box.

I notice a burnt rubber/plastic smell from the exhaust when the issue is present (almost every time I drive now)

The start/stopp function doesn’t work any more, no problem for me but someone asked about this earlier in the thread.

is it me or sound is similar to after turbo whoosh/spool?

 

[Kosmosnautti]

@Kallaskalle or others with the issue, did any of you figure out the root cause of the noise?

I bought a T6 with a CAAC engine and DSG transmission at the end of November last year, so I’ve had it for ~2 months for now.

Every now and then (like just a handful or so times so far) it makes this strange ”wobbling” sound, and the videos found in this and the other linked thread are the closest match to how mine sounds also.

Here’s a video I recorded today when the noise appeared again, this time I had a friend pressing gas pedal so I could try to pinpoint the source:

So a weird ”wobbling” sound, only when the gas pedal is pressed very lightly. Eventually it sounded like it came from the air filter box. I opened the box, nothing unusual inside. Put everything back together again, and the noise was gone for now. Who knows when it comes back again.

I first thought that maybe it’s something else further in the engine, and the noise just gets carried to the air filter box, like turbo or something. But now that I see some of you mentioned DPF regeneration, I wonder if that is somehow linked to it? I wonder if there’s a way to check when the regen was last done, was it done today for example? Maybe with VCDS?

 

[Kallaskalle]

@Kosmosnautti

No my sound is still present and I have still no clue :/
220000km/137000 miles now

 

[Kosmosnautti]

@Kosmosnautti

No my sound is still present and I have still no clue :/
220000km/137000 miles now

Well, luckily according to your mileage it doesn’t seem to cause any harm, it’s just very annoying. And doesn’t sound normal at all

I checked and the last DPF regen on my car according to VCDS was done exactly around that time when I recorded the video above, so at least on my car it’s somehow related to DPF regen. Haven’t heard the noise after the day the video was recorded, but I guess I’ll hear it again during the next regen.

 

[kombihouse]

Hi, I was just wondering if any one has had any luck with identifying the source of the noise? We have a T6 2016 CAAC 140 euro 5 67000 miles and have exactly the same noise. We have had the van for about three years now and the sound started just after have DMF, clutch, master cylinder and slave cylinder replaced. I don't know if it was just coincidental. We have been to every independent VW specialist we can find in Hampshire. We can another DMF replaced, gearbox reconditioned, engine mounts replaced, Aircon compressor and alternator pulley replaced. All of these have had no affect. I feel like the noise is getting worse and the note of the engine sound considerably rougher. I also feel there is more vibration from the van. I don't know if they are linked to the original noise in the previous videos of not.

I think we would just give up on the van (Otis) if it wasn't for the money we have already put in, the kids love it and the fact we would just be passing the problem on to someone else. Any help would be muchly appreciated.

 

[The Bear78]

In addition to the parts mentolned in post #48, I've also had the clutch and flywheel changed.
'No change in the noise which I'm sure is related to the air system and not the big mechanical parts. There is no relationship with a vibration anyway.
60 000 miles now since I bought the van and it's no worse.
I stopped worrying about it ages ago but, I appreciate it could develop into a bigger issue at some point.