Fixed '12 - Cold weather hesitation, stink.

ekiM · Nov 9, 2017

Other than a bizarre collapsed VGT hose issue, our EPA compliant Passat has been working fine... then it got cold out.

Now when it's below 50degF out and after cold start the car exhibits the following:

Loud as all hell - In addition to normal Diesel sounds turned up to 11, it sounds like there's a single marble banging around in there.
Exhaust smell - Leave the door open while the car is on and your sinuses will pay.
Hesitation - You have to dig deep to keep it from falling on its face from a stop. Under light throttle "bucking" can be felt.

All this goes away right after the temp gauge reaches the first tick. My wife even mentioned it to me, which is really bad... she never notices this stuff.

tdiatlast · Nov 9, 2017

(noise) How many miles? DSG or 6 speed?
Any possibility the DMF is going out (unrelated to the fix)?

ekiM · Nov 9, 2017

tdiatlast said:
(noise) How many miles? DSG or 6 speed?
Any possibility the DMF is going out (unrelated to the fix)?

It's a DSG, so an obvious nope to DMF: 88k on the clock. It all totally goes away once warmed up.

jrm · Nov 9, 2017

Yes to all, I wrote on here a few months back about ours smelling like a mobile cat box, the urea injection is intense at idle during regeneration. Mine also is extremely noisy (like louder than a ALH) when cold, sounds like its moving the timing all over the place as it will rattle loud, then quiet then loud again all during the same RPM and load- once warm its ok and close to pre-fix behavior

d2freeman · Nov 10, 2017

Same here, the loud rattle started with the fix, also stumbles badly anytime the outside temp is below 60 deg, after a mile or so the stumble is gone.
I just flipped 199k miles and as soon as I hit 230k (around May) and the warranty is up it's getting flashed. Hell I would love to get it flashed back to before the fix, it was a perfect car.

06bluebeetletdi · Nov 21, 2017

I let mine warm up for a few minutes (sel with remote starts) which helps and i also switch it over and manually upshift until i get to the highway ~2 miles.

roni024 · Nov 22, 2017

ekiM said:
It's a DSG, so an obvious nope to DMF: 88k on the clock. It all totally goes away once warmed up.

I thought DSGs DO have a DMF. Am I wrong? My DSG makes the same marble noise when cold, and I always attributed it to a DMF on its way out.

tdiatlast · Nov 22, 2017

YES, DMF is critical to the DSG to negate shifting abruptness, IIRC.

So YES, DSGs suffer from DMF failures, although we don't read much about it here. Newer DMFs seem to be more robust than early iterations.

Acoustics_Guy · Dec 4, 2017

I'm late to this conversation so if you solved this issue, then disregard.

My 2013 Passat had the same symptoms you are getting.

Loud as all hell - In addition to normal Diesel sounds turned up to 11, it sounds like there's a single marble banging around in there.
Exhaust smell - Leave the door open while the car is on and your sinuses will pay.
Hesitation - You have to dig deep to keep it from falling on its face from a stop. Under light throttle "bucking" can be felt.

All started really soon after the fix. (Probably within the week)
Dealer refused to look at it as no check engine light was on. Said it was fine.
I Drove it for about 2 months when the car finally threw a code.

Dealer diagnosed fuel injector #2 was bad and Replaced it under warranty. All of the above mentioned issues are now gone.

Bummer that I had to wait until the check engine light went on for a performance issue that was obvious.

Hope that helps anyone reading this.

VeeDubTDI · Dec 4, 2017

ekiM said:
Other than a bizarre collapsed VGT hose issue, our EPA compliant Passat has been working fine... then it got cold out.
Now when it's below 50degF out and after cold start the car exhibits the following:
Loud as all hell - In addition to normal Diesel sounds turned up to 11, it sounds like there's a single marble banging around in there.
Exhaust smell - Leave the door open while the car is on and your sinuses will pay.
Hesitation - You have to dig deep to keep it from falling on its face from a stop. Under light throttle "bucking" can be felt.
All this goes away right after the temp gauge reaches the first tick. My wife even mentioned it to me, which is really bad... she never notices this stuff.

I think you might have a bad fuel injector. A few people have posted about nailing (that loud single marble in the cylinder sound) and bucking problems that have been corrected when the dealer replaced a fuel injector.

jrm · Dec 4, 2017

mine is starting to nail a lot and its even noticeable at freeway speeds, sounds like someone loosened up a rod cap. No codes yet

ekiM · Dec 5, 2017

VeeDubTDI said:
I think you might have a bad fuel injector. A few people have posted about nailing (that loud single marble in the cylinder sound) and bucking problems that have been corrected when the dealer replaced a fuel injector.

Yup, that's what it was. They replaced all four injectors and we're back to normal. It's weird that it only did it cold, but I'm guessing the cold-start injection strategy has changed a bit.

roni024 · Dec 12, 2017

How does someone diagnose a faulty injector, short of just swapping a new one in each and checking for improvement? That could be a pain since each injector needs to be coded with VCDS to match accordingly.

Fixed '12 - Cold weather hesitation, stink.

ekiM

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tdiatlast

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ekiM

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jrm

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d2freeman

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06bluebeetletdi

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roni024

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tdiatlast

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Acoustics_Guy

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VeeDubTDI

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jrm

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ekiM

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roni024

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