Idle Misfire Sound?

jetpackjbd

Well-known member
Joined
Jan 23, 2024
Location
Lithia, FL
TDI
2011 Volkswagen Jetta TDI DSG
My 2011 Jetta TDI sounds like it misses combustion every few seconds, but I have no error codes and the RPM stays consistent. Especially when cold. Maybe it’s a vacuum leak and it’s hunting a bit? Didn’t think that was a thing on diesels
I’ve attached a video of it idling, any thoughts on what the problem is/if there’s a problem?

 

STDOUBT

Veteran Member
Joined
Jul 30, 2007
Location
Portland, effing Oregon
TDI
dos jettas
Maybe it's just me (or the audio quality), but it sounds more like something's loose and rattling versus a misfire.
Like how a single mass flywheel will do the shimmy sound at idle.
 

jetpackjbd

Well-known member
Joined
Jan 23, 2024
Location
Lithia, FL
TDI
2011 Volkswagen Jetta TDI DSG
Maybe it's just me (or the audio quality), but it sounds more like something's loose and rattling versus a misfire.
Like how a single mass flywheel will do the shimmy sound at idle.
Yeah, it seemed strange that it would “misfire” for 3 seconds and not lose RPM. The motor wiggles a lot at idle and occasionally makes the interior of the car chatter. Another point towards flywheel issues?
 

ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
Dual Mass flywheel is my $$....it's getting stuck or failing I believe

The tell I believe is steady RPM but the noise
Some people do convert to single mass ones to save $ and possiblity eliminate THAT problem...but that a whole new debate about new added problems beyond NVH
 

jetpackjbd

Well-known member
Joined
Jan 23, 2024
Location
Lithia, FL
TDI
2011 Volkswagen Jetta TDI DSG
Dual Mass flywheel is my $$....it's getting stuck or failing I believe

The tell I believe is steady RPM but the noise
Some people do convert to single mass ones to save $ and possiblity eliminate THAT problem...but that a whole new debate about new added problems beyond NVH
What exactly does it mean for it to be “failing”? Is the assembly falling apart?

What do I have to worry about happening? Is it just going to get louder, or will it potentially cause clutch issues or even engine bearing damage? This car was cheap and I’d rather not spend money if it’ll just make it less noisy, but I’d also like to get a few more tens of thousands of miles out of it.
 
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nokivasara

Veteran Member
Joined
Jan 25, 2008
Location
Sweden @ Lat 61N
TDI
Tiguan 4-motion, Golf mk7
What exactly does it mean for it to be “failing”? Is the assembly falling apart?

What do I have to worry about happening? Is it just going to get louder, or will it potentially cause clutch issues or even engine bearing damage? This car was cheap and I’d rather not spend money if it’ll just make it less noisy, but I’d also like to get a few more tens of thousands of miles out of it.
Worst case scenario is that it comes apart and goes through the bellhousing, potentially damaging whatever else that is in the path of the debris.
I you just need some more miles out of it you can keep driving, it may last a long time still if the sound has started just now.
 

jetpackjbd

Well-known member
Joined
Jan 23, 2024
Location
Lithia, FL
TDI
2011 Volkswagen Jetta TDI DSG
Worst case scenario is that it comes apart and goes through the bellhousing, potentially damaging whatever else that is in the path of the debris.
I you just need some more miles out of it you can keep driving, it may last a long time still if the sound has started just now.
Good to know, I’m not really sure how long the sound has been prevalent unfortunately. I always assumed it was just normal diesel chugging noises.
Eventually, when I feel like spending almost what I initially paid for the car, I’ll take it to a specialist or even a dealership. It needs an oil cooler, transmission fluid change, timing belt, and apparently a DMF so it makes sense to just get everything done at once. Probably should replace the clutches too.
 

privateTDIjet

Veteran Member
Joined
Jun 21, 2022
Location
Montreal, Canada
TDI
2009 Jetta 2.0 TDI and 2014 Passat 2.0 TDI / Ive got a MK5 bentley manual, message me for a free diagram
I drove on my bad DMF for 3 months. Towards the end it started being a consistent sound while idling or stopped. Yours does sound much more consistent though...
 

jetpackjbd

Well-known member
Joined
Jan 23, 2024
Location
Lithia, FL
TDI
2011 Volkswagen Jetta TDI DSG
I drove on my bad DMF for 3 months. Towards the end it started being a consistent sound while idling or stopped. Yours does sound much more consistent though...
By “towards the end”, do you mean when you got it replaced, or when a major failure occurred?
 
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