Runs rough Jerks for 2 minutes, then?

scottohackett

Member
Joined
Sep 20, 2016
Location
cincinnati
TDI
2012
I am new to the forum first off. I have a 2012 TDI PASSAT that just started acting up maybe 10,000 miles ago. I have 128,000 miles on it. Here's the issue. If I get in the car whether its cold OR hot out it runs rough, doesn't stall but jerks. This happens right at the 27-30 mph zone. The MOMENT the temp gauge moves it goes away and runs like top and will for the rest of the day but the moment the car sits over night same issue. So basically the issue only lasts maybe 1 mile and than wolla its gone. I took it to the dealership and they checked the injectors, all fine. They heard the knocking which last maybe a few minutes and then it goes away. They said next step was to tear off the top end and start looking for cam issues etc. Don't want to sink aton of cash into it but,,, You can start the car every morning and rev it out to 3-4,ooo rpm and it doesn't stumble run rough or anything. Issue only happens under load. Its almost as though something needs to build pressure and then when it does its TOTALLY fine. Any idea?
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Has it always done this before, or is this a new problem?

Passats have an emissions warm-up mode that actuates a throttle valve in the exhaust system during warm-up in order to get the emissions components up to temperature. During this process, you will feel the power delivery being harsh or jerky (well-documented here, and completely normal).

Revving the engine out to 3000-4000 RPMs when cold is a good way to blow your turbo. The warranty is only good until 120,000 miles, and these turbos are small, fragile, and a bit over-worked when cold. Best practice is to drive gently and smoothly until the emissions warm-up routine has finished. This usually takes about one mile of driving after you first start.
 

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
My 2013 (117k) does the same thing, although it seems more common under 60degF.

I have learned to minimize the hesitation by driving it in M mode and keeping the car under 3rd gear while the transmission warms up. Luckily, I live a few blocks deep in a slow-speed neighborhood so I can warm it up this way.

Even when I reach roads with a higher speed, I still keep it in M mode until I reach 4th.

I have found the hesitation occurs in 3rd gear at around 1700 RPM when the engine and, particularly, the tranny are cold.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
If you have a ScanGauge, you can watch the boost and exhaust temperature behavior during this warm-up mode (that causes the jerking you both describe). If you have VCDS, you can actually watch the exhaust throttle moving as you change accelerator pedal position. It's this exhaust throttle movement and changes in exhaust backpressure that causes the jerking feel. It will only do it in 3rd gear and higher, and only for a brief time after about one minute of driving. It does it until the DPF temperature reaches about 800 F, then it stops (it's actually waiting for the SCR to come up to a specific temperature, but I don't know exactly what temperature that is).

This is also known as turbo blow-torch mode, which is why you should drive gently when it's happening. The 23N5 software update reduces turbo boost on a cold engine, which has helped reduce the number of premature turbo failures, but I still wouldn't press my luck by driving aggressively or accelerating briskly when the engine is cold.
 
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scottohackett

Member
Joined
Sep 20, 2016
Location
cincinnati
TDI
2012
This is a new problem that started about 10,000 miles ago. I am a lubrication engineer so obviously everything is synthetic hence turbo heat. I don't rev the engine like that I was just giving another piece of the puzzle stating when I did rev it no issues only under load for rough running. I do baby it for the first 2 minutes of jerky driving as to not make something worse.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Since this problem has developed recently, it may be possible that your exhaust throttle valve is starting to get sticky (another common issue on the commonrail TDIs). You might want to crawl under the vehicle to verify that it is moving/functioning freely and not getting stuck part way.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Approximately under the gear shift, you'll see this device:



You can remove it and check it for operation. You may also be able to run it through its range of motion without removing it from the vehicle. You'll want to be on the lookout for corroded mechanical connections, and/or it sticking at some point during its range of motion.

https://www.youtube.com/watch?v=HE6Y2pY9gW4
 

goldgary

Well-known member
Joined
Sep 16, 2008
Location
NH
TDI
2012 Passat 6M
My 2012 manual has done this since new. VEE DUB TDI seems to have it nailed down to the issue. I wouldn't put any money in it. Just live with the little quirkiness which is TDI.

Gary
 

scottohackett

Member
Joined
Sep 20, 2016
Location
cincinnati
TDI
2012
Its just weird that it suddenly started now. It hasn't thrown any codes or anything. will research more about the flapper vavle he mentioned.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Top end lifter noise when cold is also commonly reported on the CKRA engine (which is what you have). Volkswagen replaced a few sets of lifters on vehicles that were under the bumper-to-bumper warranty, but most of us have chocked this up to normal behavior and haven't bothered to do anything about it. Lifter noise is unrelated to the problem you're describing in this thread.

I also don't think this is a transmission issue. We also have the DSG transmission - same as you.
 

scottohackett

Member
Joined
Sep 20, 2016
Location
cincinnati
TDI
2012
Its just weird that the MOMENT the knocking noise goes away so does the running rough and everything SOUNDS and runs perfect. It just throws me off. Worse thing was dealer had car for 4 days and couldn't figure it out and said all looks good unless we tear into the engine.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Dealers really don't even know what they're looking at, much less how to diagnose a problem. VW's troubleshooting involves mechanics reporting the problem to a common "tech line," and receiving troubleshooting information from Germany. If there isn't a check engine light and a stored diagnostic trouble code, they don't even have anything to report to Germany.
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
Its just weird that the MOMENT the knocking noise goes away so does the running rough and everything SOUNDS and runs perfect. It just throws me off. Worse thing was dealer had car for 4 days and couldn't figure it out and said all looks good unless we tear into the engine.
The knocking noise is related to the exhaust flapper as during the emission system warmup the #4 injector fires on the exhaust stroke and if that flapper is not opening enough some fuel will be left in the cylinder due to all that back pressure causing a bit more of a knock on that cylinder. when the warmup is done the computer changes the injection timing and stops sending fuel down the exhaust. So, check out that exhaust flapper for proper movement as it may be holding to much exhaust back- carbon buildup can cause the problem to surface over time :D
 

scottohackett

Member
Joined
Sep 20, 2016
Location
cincinnati
TDI
2012
Would the knocking still sound as though it's coming from the top end of the motor and I assume all I need to do is push the spring and see if it sticks
 

Herkguy

Veteran Member
Joined
Feb 11, 2013
Location
minneapolis
TDI
2013 passat SE sun/nav
If I remember, the exhaust valve is under warranty now to 120k also.
Might have the dealer check that for you.
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
knocking will sound like its in front of the glovebox
 

r11

Veteran Member
Joined
Mar 6, 2012
Location
NJ
TDI
2012 Passat TDI SE 6MT (BB'd), 2015 Passat TDI SE 6MT
Mine been doing it since day 1 - first 2 minutes after cold start. Well known issue, we discussed it here in depth. Mine is 6MT, 3rd gear is the worst offender, less pronounced in 4th.
 

laminated

Veteran Member
Joined
Apr 28, 2004
Location
Canada
TDI
15 Sportwagen
my 13 did the same since day one,, was told to the dealer before the 20K as well. that and several issues are why this car is heading back asap...
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Let's not confuse valvetrain tick with knock from injection timing. jrm's video that he posted a while back is clearly not valvetrain noise, but many people experience valvetrain noise and may confuse it with the description of combustion knock.
 

03fan

Well-known member
Joined
Oct 7, 2015
Location
Wisconsin
TDI
2013 Passat TDI SE 6MT
Mine been doing it since day 1 - first 2 minutes after cold start. Well known issue, we discussed it here in depth. Mine is 6MT, 3rd gear is the worst offender, less pronounced in 4th.
Mine is the same as yours, but 4th gear instead of third. I typically keep my 3rd gear under 2k rpm's before shifting. This might be why mine is different.
 

03fan

Well-known member
Joined
Oct 7, 2015
Location
Wisconsin
TDI
2013 Passat TDI SE 6MT
Mine seems to be getting worse with the colder temps. I think it's time to park it and wait for the buyback. Not willing to gamble and keep driving it.
 

Rabert

Active member
Joined
Aug 19, 2014
Location
Fort Worth, TX
TDI
2012 Passat
I had a similar issue with the stumbling then knocking sound. After 3-4 weeks at the dealer they replaced the turbo to eliminate the stumbling. The knocking was eliminated by replacing an injector. Search for threads with my userID, I had an audio recording where you could hear the knocking, vaguely, but it is there. Thanks!
 

Rabert

Active member
Joined
Aug 19, 2014
Location
Fort Worth, TX
TDI
2012 Passat
I had a similar issue with the stumbling then knocking sound. After 3-4 weeks at the dealer they replaced the turbo to eliminate the stumbling. The knocking was eliminated by replacing an injector. Search for threads with my userID, I had an audio recording where you could hear the knocking, vaguely, but it is there. Thanks!
 

JETaah

Vendor , w/Business number
Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 1999.5 jettaIV,2005 BEW Beetle
I just had a similar set of symptoms as the OP on a customer 2012 Passat with 271K miles. The symptoms just started consistently occurring last autumn when the temps dropped below ~ 40*F.
After a couple of minutes/miles running, it all cleared up and you wouldn't know that there was any issues until the next cold start.

I tried to log the injector balance, fuel pressure, and boost during the test drive and nothing looked like it was faltering. Exhaust flap was moving without issue both manually and with the output tests.
To me, it felt like an injector was missing but I could not find the data to confirm this. The VW dealer, (Vyletel VW), tapped him for close to $2800 trying to figure out what his problem was with no success.

Given that the injectors had 271K on them, the owner decided to take a shot and purchase new ones to replace them. He located a set of the new solenoid type injectors that are now obsolete, p/n 03L130277R, from an on-line VW dealer and I installed them. The rough-run symptoms have not yet reoccurred.

Happy customer! They are blowing out the injectors for around $220 each.
The latest revision of injectors are going for about $420 each.
I don't know if this will help anyone else but thought that I would pass on the info.
 
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jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
Good to know, sounds like the warmup mapping is not getting along with older injectors for whatever reason- :confused: 271K on a stock (non deleted) vw is impressive!
 
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