Passat 125kw TDI vibration and resonance at 1200rpm-1500rpm

[mebius9]

My car developed this annoying vibration or resonance which occurs from
1200rpm all the way to 1500rpm (even on neutral gear)
I mean this car pretty much lives at around that rpm range
and frankly it's driving me nuts

is anyone suffering from similar symptoms?

I test drove Tiguan 103TDI the other day and it was whisper quiet...

[Greg Roles]

The Passat has an additional engine balancer shaft over the GT's 125 engine, but my money is on the Dual Mass Fly....but best head back to the dealer mate!

[mebius9]

The Passat has an additional engine balancer shaft over the GT's 125 engine, but my money is on the Dual Mass Fly....but best head back to the dealer mate!

Don't failing Dual Mass Flywheel give you more of a shake then resonance?
anyway I didn't know GT 125 didn't have balancer shaft thought it was the same engine?

[Greg Roles]

Balancer shaft only on Passat, GT Golf comes without.

Apart from the balancer shaft, they are identical.

[mebius9]

I've taken it to couple of different dealers
and only one of them agreed there is resonance...
you can tell that they are trying their best to avoid fixing it.

Anyway I figured it's got something to do with the air intake pipe
I'm guessing three possible causes:

1. Cam timing is little off creating resonance at the air intake
2. Turbo air intake piping has hole somewhere due to misalignment
3. Air intake flap is vibrating. ( if such thing exists in this car)

#Condition is replicable with the car in neutral which means DSG/Wet Clutch is not the cause.
#Placing hand over the air intake stops the resonance

Anyone with BMR engine Passat around Rowville area to help me?

[Greg Roles]

So it only does it at those RPM's and the amount of boost ( throttle ) doesn't alter it? Say you drive along and at 1200 slowly accelerate, it doesn;t get massivley louder if you step on it? Seems odd that you can stop it with your hand, so i's obviously airflow related....hmmm...

Is it drumming, cyclic, deep, high, an exhaust "type" noise, whoosh, pssst??

[mebius9]

So it only does it at those RPM's and the amount of boost ( throttle ) doesn't alter it? Say you drive along and at 1200 slowly accelerate, it doesn;t get massivley louder if you step on it? Seems odd that you can stop it with your hand, so i's obviously airflow related....hmmm...

Is it drumming, cyclic, deep, high, an exhaust "type" noise, whoosh, pssst??

Amount of throttle seems to have no effect on it.
It's almost certainly airflow related from what I've observed so far.
To describe the sound more accurately it's deep boomy noise


If you got a decent sound system it almost exactly like this actually:
YouTube - 50 hz

Extremely irritating after about 10 minutes

[theshark]

Hi Mebius9,
I bought a Passat 118TSI recently. It's the latest model just released in May, and apparently it's a petrol car with 7 speed DSG. I found similar resonance when engine rev is around 1200 RPM when I was coasting to a stop. Also I found below on "Australian New Care Buyer" magazine 2011 No. 36 with regards to Volkswagen Passat,

"Noise, vibration and harshness levels are low, although our test car had an annoying, inexplicable resonance which seemed to emanate from the drive train on a trailing accelerator at 80-100km/h, or as it coasted to a stop."

Have you got it sorted out? I'd like to know the outcome of your case. I'm going to speak to the dealer with regards to the resonance this weekend anyway. I probably will send an email to Volkwagen Australia as well to see what they would say.

Cheers,
John

[TDI DSG]

Hi Mebius9,
I bought a Passat 118TSI recently. It's the latest model just released in May, and apparently it's a petrol car with 7 speed DSG. I found similar resonance when engine rev is around 1200 RPM when I was coasting to a stop. Also I found below on "Australian New Care Buyer" magazine 2011 No. 36 with regards to Volkswagen Passat,

"Noise, vibration and harshness levels are low, although our test car had an annoying, inexplicable resonance which seemed to emanate from the drive train on a trailing accelerator at 80-100km/h, or as it coasted to a stop."

Have you got it sorted out? I'd like to know the outcome of your case. I'm going to speak to the dealer with regards to the resonance this weekend anyway. I probably will send an email to Volkwagen Australia as well to see what they would say.

Cheers,
John

I'm having this issue at the moment with a diesel similar to mebius9.
Please post up how you go with the dealer, as I have had no luck thus far. Have been told it's normal.
Some people (me) are more prone to picking up the annoying frequency than others.
A quick google shows it's not uncommon in diesels - not found any mention of it for the TSI though !

[ST33VI]

Has it still got the baffle thingy in the air box under the filter??? maybe sumone has taken it out.

[TDI DSG]

Has it still got the baffle thingy in the air box under the filter??? maybe sumone has taken it out.

Would you mind elaborating on this please ......

[theshark]

Has it still got the baffle thingy in the air box under the filter??? maybe sumone has taken it out.

Thanks for your help ST33VI. Sorry I am newbie here. Can you please elaborate more with regards to baffle in the air box?

[ST33VI]

with and without baffle

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-ash4/254510_10150191222637623_532602622_7339807_1314566_n.jpg

[Greg Roles]

Good thinking, but I reckon it wouldn't make a difference given there is a thick paper element right over the top of it to stop any standing waves. Resonance like that is more overall volume than grids, and I think if you uncoupled the airbox and took a drive, you could see if it is something like that.

[theshark]

Thanks mate. I changed the second link from URL to IMG.

Sounds like a lot for me to learn. Do you reckon the resonance is caused by the baffle in the air box? I do feel the resonance is from the drive train though.