Turbo noise (not air/pressure)

jessenator

Member
Joined
Jul 15, 2019
Location
Utah
TDI
2012 Jetta Sportwagen
Greetings all,

I know noise diagnoses can be a joke amongst car people, so I'll do my best to paint a proper picture.

2012 Jetta Sportwagen - DSG - 112k miles - stock—Since the sound comes on right around 2,000 rpm as the turbo starts to spool, and drops off on upshift, I can only assume it's the turbo:

it's a quiet, yet distinct metallic, almost grinding, or tinkling sound—as it's coming through the firewall, it's a bit dampened. It's definitely metal on metal. The more gently I accelerate, the longer the duration, but it's only 1 second or less. Giving it the beans it lasts a fraction of a second. So like right as the turbine spools up. I haven't tested it in manual mode to see if it holds, but I'll give it a go tonight.

I recently had some warranty work performed (new exhaust filter among other things), and before this, aside from the turbo lag being more pronounced because of the exhaust lack of pressure, all I could really hear was the pleasant pressure/wastegate-like noise. When I got a persistent MIL and computer malfunction light (MIL would come on and turn itself off before), I took it to the dealership to perform the warranty-covered work. ON the way to drop it off, the turbo made a weird noise, possibly from the clogged soot filter they replaced

list of what they did here:




Aside from finding and fixing a bad connection on injector 4, nothing else came up in their multi-point inspection. I know dealerships have bad reputations, but I'm glad they were at least that concerned to look.

Is this noise something I should be concerned about? Should I take it back to them? ignorance talking: I was told that everything save the block was covered in the emissions/dieselgate warranty, including the turbo, but please, PLEASE correct me there. Also, I discovered they can't do anything until there's an MIL on, which prolonged my JSW's stay at the dealership (it would turn itself on and off)

Normally I wouldn't be such a worrywart about a strange sound on a used vehicle with over 100k miles, but if the grinding is sending metal shards into the cylinders, I don't want to wait that one out…

Thanks for the advice, and let me know if more detail is needed.
 

jessenator

Member
Joined
Jul 15, 2019
Location
Utah
TDI
2012 Jetta Sportwagen
In manual mode it persists when I hang right around 2k RPM. same noise, hasn't really gotten louder or more intense. But like I said, it's very brief when putting the hammer down. I like a more tempered driving approach though.

I did notice that day after opening my hood they neglected to replace the plastic engine cover. I've heard it's mainly for noise dampening, so maybe this is a normal noise and I'm just not supposed to hear it? But then again I'm completely new to VWs, so there's that.

If it's not something to worry about, I'll just keep driving. Also, managed to get 36/52 (44) average today on mild mountain highway driving, so that's decent.
 

Nemo312

Member
Joined
Jan 11, 2019
Location
Seattle
TDI
2013 VW Golf TDI
Sounds like it might be your catalytic converter to me, little piece is broken in there and rattles when more air comes through. It could also be a piece of heat shielding or exhaust is touching something underneath the car and is vibrating, this doesn't seem like a turbo problem though...
 

Nemo312

Member
Joined
Jan 11, 2019
Location
Seattle
TDI
2013 VW Golf TDI
Also could be something in the dpf rattling, in routine maintenance they are scheduled to be checked at 120k miles
 

JELLOWSUBMARINE

Veteran Member
Joined
Mar 3, 2014
Location
yes
TDI
2011 JSW 2008 E350 6.0
jessenator said:
Dealer left the cover off? Yes its a sound deadner. I would question the techs thouroughness of repair @ minimum and request it be replaced. Dealer repairs shouldnt be that sub standard.

Note on the repair order the sound and your concern. If there is a problem and its not addressed then later fails out of warrenty youll have a fighting chance
 
Last edited:

jessenator

Member
Joined
Jul 15, 2019
Location
Utah
TDI
2012 Jetta Sportwagen
Thanks for the responses.

Dealer left the cover off? Yes its a sound deadner. I would question the techs thouroughness of repair @ minimum and request it be replaced. Dealer repairs shouldnt be that sub standard.

Note on the repair order the sound and your concern. If there is a problem and its not addressed then later fails out of warrenty youll have a fighting chance
I'm fairly positive— I test drove several TDI JSWs the day I bought mine, and I may be getting my wires crossed. I stopped by the dealership this morning on my way to work and filled them in. Hopefully I'll get a response today.

Yes, I'm hoping to get it all worked out before the 120k mark…here's hoping.

Since all the work's been done it's been fine. So far about 500 miles put on and it's been nothing but fantastic. 44MPG is a great thing to see at the end of a drive, especially having come off a Jeep Cherokee XJ and its high teens digits.

It very well could be the cat. Like I say, I'm new to VWs and that seems to be a common noise maker, especially after the exhaust system has been worked on.

The only thing that concerns me is that is sounds rotational —I don't know a better way to describe it—it's like a more quiet, less-intense sound similar to an angle grinder coming to a stop (minus the electric motor noise) or putting on a brake drum. I don't have a good recorder, but I'll try and get a sample.
 

jessenator

Member
Joined
Jul 15, 2019
Location
Utah
TDI
2012 Jetta Sportwagen
Alright. Sorry it took so long but here are some vids (audio is more important) and thankfully the sound does come through, despite the normal engine sounds. I did two and even though they're about a minute or less a piece, I didn't edit them.

https://drive.google.com/open?id=1-LRCSEVPFyXc_55OP9TCxD3TSD8z3Wir
https://drive.google.com/open?id=1-4v4FahRF2aCrn5reJUbki8z0TEsFwNN

I was just keeping it in manual and trying to hold it where the noise was loudest ...it's much louder with the window down :/
 

jessenator

Member
Joined
Jul 15, 2019
Location
Utah
TDI
2012 Jetta Sportwagen
Well, I took it and and got it back the same day.

Turns out it was a "failed" exhaust bracket, nothing more… well I'm glad that's all it was, but feel kinda sheepish for how big of deal I was making it (what else is new in my life? hah.) Also good that it was marked to be taken care of under warranty, so no more charges.

Resonance is a funny thing. Just right there at that amount of exhaust pressure could cause a vibration.
 
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