2012 VW Golf TDI - Bad DPF declined by VW

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
I say just find the sketchy sensor and replace it and no more problems. Or at least the P2002 will go away.

But IMO the dealer blaming the K&N is not totally out to lunch even if it might be something of a stretch. Over the years I've seen too many failed maf sensors with a K&N to ignore that possibility, regardless.

and check for the boost leak at the o-rings
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
probably beating a dead horse here, but might be worth repeating.

K&N may help on an old carbureted gasser or any gasser where the power output is directly affected by airflow. You can practically dyno a gasser by the maf reading. BUT our TDI's are NOT airflow limited. They are a lean burn by their very nature and adding slightly more air (as these filters claim) will NOT add power. repeat after me.... FUEL THROTTLE

In fact the air charge is regulated in a closed loop in the 2015 USA market cars, so any additional airflow will be cut back by the ecu anyway making any potential gains a moot point.

of course these statements are a vast oversimplification but hopefully convey the applicable concepts in a general way

from a practical point of view, the OP will need to pass the california emissions inspection. I don't think they allow any CEL. So he may be able to get by for the time being by finding the errant sensor and or boost leak and get that CEL tooken care of without having to go thru the whole dpf replacement thing.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,

NorCalTDI79

Member
Joined
Sep 6, 2018
Location
Folsom, CA
TDI
2012 VW Golf TDI
probably beating a dead horse here, but might be worth repeating.

K&N may help on an old carbureted gasser or any gasser where the power output is directly affected by airflow. You can practically dyno a gasser by the maf reading. BUT our TDI's are NOT airflow limited. They are a lean burn by their very nature and adding slightly more air (as these filters claim) will NOT add power. repeat after me.... FUEL THROTTLE

In fact the air charge is regulated in a closed loop in the 2015 USA market cars, so any additional airflow will be cut back by the ecu anyway making any potential gains a moot point.

of course these statements are a vast oversimplification but hopefully convey the applicable concepts in a general way

from a practical point of view, the OP will need to pass the california emissions inspection. I don't think they allow any CEL. So he may be able to get by for the time being by finding the errant sensor and or boost leak and get that CEL tooken care of without having to go thru the whole dpf replacement thing.
Thank you!! Appreciate this. May have to go to my independent as I'm sure the dealer will not do this :cool:
 

NorCalTDI79

Member
Joined
Sep 6, 2018
Location
Folsom, CA
TDI
2012 VW Golf TDI
Thank you!! Appreciate this. May have to go to my independent as I'm sure the dealer will not do this :cool:
Funny thing, over the weekend after not driving the car for three days the CEL was off upon startup in the morning.

I am going to see about properly diagnosing it as the dealer is pretty useless at this point.

Still working with K&N at getting a claim going.
 

Kevinski4

Vendor , w/Business number
Joined
Aug 31, 2007
Location
Nebraska
TDI
.
It has always been puzzling to me why anyone would bother to use these air filters in the first place, as they do NOTHING positive, and you cannot force feed a tiny little turbocharger by installing one anyway.
However, given the all-too-common issue of the DPF cracking (Volkswagen has a TSB about this, nothing new), and the fact that there is pretty much zero chances of an aftermarket air filter causing this*, I don't know what to say. Besides, no idea why the dealer would really care one way or the other, Volkswagen is the one footing the bill, and it isn't likely they are requesting the old air filter from the car. That is just dumb.
*now, increased cylinder bore wear, turbine blade wear, and yes MAF values being off as well as outright failure, can and does happen with these subpar air filters. It has been proven in labs outside those of K&N, but the marketing folks are still making money. So, I'd say let K&N fight for you... I still think they'll do nothing.
I've seen a lot of cars with cracked DPFs later on in their life. I've also seen a handful that cracked VERY early (25-35k miles). Every single one of those cars that had very early (and in two cases, repeated) DPF failures (cracked) had aftermarket "high flow" air filters or air intakes on them. So from what I have seen, there is definitely a direct correlation between the accuracy of the MAF scaling and the life of the DPF. Which shouldn't be that much of a surprise, really.
 
Last edited:

06bluebeetletdi

Veteran Member
Joined
Sep 30, 2012
Location
Middlesex, NC
TDI
'14 Passat TDI SEL and '13 Beetle TDI
I have a small battle on my hands between VW of America and the local dealer (Folsom Lake VW) after it has been determined that CEL & code P2002 that the DPF IS bad. Soot in the tailpipe and build up in the DPF filter that the DPF/catalytic converter assembly need to be replaced on my 2012 VW Golf TDI The dealer and VW of America is refusing to help after their Master Tech noted that my car had a replacement K&N Filter element in the factory airbox. Nobody at the dealer has ever made mention in the past that this could potentially void the warranty.
How many TDIs do dealers see now? Next, how many have k&n filters? Then, how many have had warranty denied for this reason? The dealer probably didn't know about this unlikely situation, and wouldn't have thought anything about it, other than the usual recommendation to stick with the stock filter as that is what the engine was designed for.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Agreed, with dealers not knowing majority of the failure modes for TDIs, they certainly won't know X part or Y thingy will void warranty until VWoA tells them it's voided.
 
Joined
Dec 30, 2018
Location
Pennsylvania
TDI
14 golf tdi dsg
OP.....if im not mistaken doesnt the magnusson moss act require dealers or manufacturers to PROVE that (in this case) the K&N filter DIRECTLY CAUSED the failure of the equipment to be fixed under the warranty? Your response from the volkswagen rep stated that the filter you used "may" or "could" have attributed to your issue......but i bet they would have an uphill battle convincing a judge that your air filter IS the direct cause of the failure.

Maybe im wrong....just my opinion.....which is worth exactly what you paid for it
 

bizzle

Veteran Member
Joined
May 21, 2013
Location
Southern California
TDI
2015 GSW SEL (totaled), 2013 Touareg Executive
Long but useful read about MM and modifications.

https://www.golfmk7.com/forums/showthread.php?t=7492

K&N is much less of a modification, but can still be ground for the dealer to stand on to deny coverage.
While it's important to not believe in the myth of a "golden ticket" for mods, it's also equally important not to swing entirely the other way and believe that nothing is allowed.

The person in this thread stated the filter was a standard replacement for the stock filter and installed in the stock housing. A drop in filter, regardless of manufacturer, is going to qualify as general maintenance in a way that a *cone* filter fitted to an aftermarket CAI would not.

Regardless, the issue is realistically moot since, for hopefully obvious reasons, this specific case doesn't have much chance of making it in front of a judge (and not because the client is wrong).
 
Joined
Dec 30, 2018
Location
Pennsylvania
TDI
14 golf tdi dsg
This is a response from the VW case manager:
The use of aftermarket air filters is not supported as the system was designed and calibrated to work with factory air filters. Use of aftermarket air filters such as cotton bed steel mesh or cone style, can cause the MAF sensor to not read accurately, affecting vehicle performance and critical monitoring functions for the diesel particulate filter. At this point it has been determined the failure is due to your aftermarket air filter and repairs would not be covered under warranty.
Thanks for the suggestions and discussion on this.
I hate to keep beating on this topic but the response vw provided to you really grinds my gears for several reasons.

1. The use of aftermarket filters is not supported....essentially requiring you to use the "Factory" air filters that the vehicle is "calibrated" for. That statement appears to contradict what i have read about mm. A manufacturer can not require that you use only their brand of product when suitable competitor products are available.

2. "At this point it has been determined the failure is due to your aftermarket air filter". What data are they using to reach this conclusion?
Did they bench test you MAF sensor along side a new MAF sensor and see extreme differences in the readings? My guess would be no. That statement is wishful thinking without any objective data to support it.

They are trying to pass the buck and are hoping you will just go away and let them. Dont...take their ass to court.
 
Top