rough idle, 5-spd

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
Okay, now I'm with you. I've heard of adjustments to those screws having an influence on the rough-idling situation. But, those screws are supposed to be very precisely set according to a procedure in the service manual. What adjustment procedure are you using?
 

NewJettaTDI

Member
Joined
Sep 11, 2005
Location
Michigan
TDI
Jetta, 2005, Gray
Rough Idle on my TDI

Mine has been for 40000 miles. It started after my 5000 mile check up at the dealer. I happened in the driveway of the dealership. Thought it was air in the fuel filter or lines. I think the tech changed some setting and caused the problem. When I returned it, they said the fuel tank needed to be drained because it had contaminated fuel. I said no to $400.00 worth of cleaning. They called the other day and wanted to know why I haven't returned. :mad:
 

ReverendVW

Member
Joined
Aug 9, 2007
Location
Spokane, WA
TDI
VW Shop Owner
I'm thinking a poor adjustment could possibly cause this issue. Most of the problem seems to go away when something in the car is turned on to cause a load. Injection quantity is adjusted mechanically and electrically. the solenoid opens to allow the pressure the cam built up out the nozzle.
Not having one here, with this problem, the only thing I can think of is the computer may be trying to compensate for the mis adjustment too much. but when you load it, it will automatically allow more fuel.?.?

Maybe they are adjusted wrong from the factory. I've had alot of mis adjusted lifter problems on factory vanagon motors. I human being is still involved in building the engine.

I apologize again for breaking into this conversation with the mkIV problem.
 

Zedbra

Veteran Member
Joined
Feb 26, 2006
Location
Squamish, BC
TDI
2005 Jetta TDI
Maybe I should have come here first before going back to the dealer with my car shaking violently. It just started about 10k ago and it is very annoying.

Dealer initially said the same thing - threw no codes so nothing is wrong. They have it again (they gave me a new TDI loaner) and I have not heard back from them. Maybe I should direct them to this thread.
 

Zedbra

Veteran Member
Joined
Feb 26, 2006
Location
Squamish, BC
TDI
2005 Jetta TDI
update: My dealer really dug into the issue, as I told them about several people having this same issue. Finally, they found that my fuel pump was only delivering 85% of the fuel it needed. Just got it replaced before my warranty runs out.
 

zanakas

Veteran Member
Joined
Mar 11, 2005
Location
PA
TDI
2005.5 Jetta 160k - original cam, clutch
Adjusting those screws without some serious prior experience might be a really bad idea...
 

Zedbra

Veteran Member
Joined
Feb 26, 2006
Location
Squamish, BC
TDI
2005 Jetta TDI
GoFaster said:
Did it solve anything?
Just got the car yesterday. It was hot here so the AC was cranked. I'll update how its running as my car was shaking all the time at idle, sometimes quite violently.

I have to compliment the tech, he kept calling me with what he was trying. He had the car for a few days and was driving it home at night to see for himself. After he didn't have much of a clue what to do, he called a master tech at VWoC and called me back, stating he had a bunch of other fuel/emission tests to try. Next thing is a fuel pump only pumping out 85% and warranty replacement. Not bad.
 

Zedbra

Veteran Member
Joined
Feb 26, 2006
Location
Squamish, BC
TDI
2005 Jetta TDI
Update - the car does not shake as bad as it did before, but I'm still feeling like I'm riding a water bed at stops.
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
I thought so. What they "fixed" wasn't the cause of the problem.

I keep telling people, it's a designed-in ECU programming issue involving how it compensates for slightly unbalanced injectors. Mine (at 128,000 km) is running smoother than it did last summer even though I've done nothing, it's probably just the injector balance shifting with time / wear / whatever. Theoretically a brand new set of perfectly adjusted injectors MIGHT solve this for a little while, until those drift from their as-new specifications, then the problem will happen again. The underlying cause (ECU programming) can only be fixed if someone goes into the programming and finds out what the real issue is, and fixes it. A dealer is NOT going to be able to do that, and given that this powertrain combination is now out of production, fixing it is not going to be high on VW's priority list. I'm ignoring mine; it's a mild irritant but it's not going to break anything.
 

nankin75

New member
Joined
Sep 7, 2007
Location
Sudbury, Ontario
TDI
2006 Jetta
Just found this site, ours is doing the rough idle too. Dealer is baffled and making calls, I am not confident at this point that he will find anything. Thanks for the info.
 

eli

Veteran Member
Joined
Oct 22, 2002
Location
I-95
TDI
2017 Cruze stickshift 2019 Terrain
best wishes with it, nankin75, and welcome to the site. the idle on mine is mostly smooth now that the weather has cooled. when it does start getting "lumpy idle", I hit the rear defogger and that has always worked to smooth it out. the car performed fine in july/august , coast to coast and back... not much idling involved in driving on I-80/90 for 6600 miles, of course...
 

lwg

Active member
Joined
Jan 16, 2003
Location
Portland, OR
TDI
2005.5 Jetta
Ours still shakes violently. Dealer didn't know what to do with it... Hoping someone finds a cure that I can take back to my dealer, they seem to listen to me quite well. Afterall, I convinced them to replace the clutch under warranty...
 

Airplane MD

Veteran Member
Joined
Aug 28, 2001
Location
Birdsboro, PA
TDI
'06 Jetta pkg 1
Due to the lack of activity on this thread, I am wondering if anyone has come up with anything definitive on this issue. My 5 speed has had Lumpy Idle from day one albeit infrequently and very light. Now with 26,000 miles it is more frequent and pronounced.

Are there any solutions out there?
 

fireice

Well-known member
Joined
Aug 29, 2005
TDI
Jetta, 2005.5 , blue
dont think anybody has figured it out yet.

my bet is on the programming and injector imbalance.

alex
few cars
 

BMac

Veteran Member
Joined
Aug 13, 2006
Location
Halifax N.S.
TDI
2015 Jetta TDI
I had rough idle last fall. Dearler replaced DMF (my tranny is DSG) and I was back to smooth idle. My rough idle was not always there. It showed up at ~35000 km.

It does appear to me that there may be a few different conditions that are giving the same symptoms.

BMac
 

2footbraker

Veteran Member
Joined
Sep 6, 2005
Location
Ontario, Canada
TDI
06 Jetta, 01 Golf
I never have rough idle and I have a SMF. I remember one time when I still had the DMF I had some rough idle after coming to a stop after a long highway drive in the summer.
 

Mach1

Vendor , w/Business number
Joined
Sep 27, 2005
Location
Spicewood, Tx.
TDI
05.5 Jetta 5 spd, 06 Jetta DE DSG, 04 F250 6L, 2000 F250 7.3L
It could be traced to POOR fuel quality as well..

I have used the Syndiesel and my Jetta, does not shake/miss/stumble at idle while I have a 50% mix in it. At 63 cetane, I would believe it has solved alot of driveability issues.
 

jjblbi

Veteran Member
Joined
Sep 27, 2000
Location
lbi, nj
TDI
2014 Passat SEL TDI
I too am experiencing an intermittant rough idle, mainly at cool down. Car is DSG, has approx. 27k miles and build date of 11/06. Hoping DMF is not planning on taking a dump... JOHN
 

TwoTone

Veteran Member
Joined
Sep 30, 2005
Location
Damascus, MD
TDI
05.5 Jetta (sold)
2footbraker said:
I never have rough idle and I have a SMF. I remember one time when I still had the DMF I had some rough idle after coming to a stop after a long highway drive in the summer.
I thought the SMF fixed our rough idle. Didn't have one for about 2 months after the install. Now it's back just like before. Good Luck
 

Evolution

Veteran Member
Joined
Nov 4, 2005
Location
Raleigh, N.C.
TDI
2015 Passat TDI SEL, Platinum Gray
Our 06 started having a rough idle at around 48k miles. The dealer couldn't find anything. I finally found that the vacume hose that runs to the air cleaner assembly had a small crack in it near the elbow at the air cleaner assembly. I trimed the peice and plugged it back in and the car ran fine. Took it to the dealer and they replaced the vacume hoses. They replaced that hose and the other hoses that that hose joins toward the firewall.
It was a small crack. The car ran rough at times, not always. I assume some flex happened during the driving of the car that closed or opened the split. Not saying this is everyones problem, but it was mine regarding this type of condition.
Also, I found a complaints on the new Passat's having vacume hoses cracking.
 
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06SpiceRedTDI

Veteran Member
Joined
Jun 12, 2006
Location
Longview, WA
TDI
2006 Spice Red TDI Jetta, 2006.5 DSG Platinum Gray TDI
I wish somebody would find a cure for this already, I try my hardest to ignore it then I am haunted by it when I drive my 1981 Rabbit Pickup that is smooth at idle, and I didn't pay close to 30k for that.
 

Airplane MD

Veteran Member
Joined
Aug 28, 2001
Location
Birdsboro, PA
TDI
'06 Jetta pkg 1
Took the car in on Monday and of course it failed to misbehave. Today as I was driving passed the dealer I took a chance and sure enough I was able to demonstrate the problem to the service manager.

Now I have an appointment for Monday for them to remove the starter and have a look at the flywheel. I will post any updates as available.
 

AudiMatt

Well-known member
Joined
May 16, 2006
Location
Gresham, OR
TDI
2010 JSW TDi DSG
Took our Jetta in about 3 weeks ago after it has had 2 new dealer installed flywheels to try to fix the rough idle issue. They had a VW service Rep come and look at the car and I guess they did some chatting with a VW engineer. I guess they have encountered a couple of cars with the chronic rough idle (hmmm) and have discovered that on some cars the timing has either slipped or is not right from the get-go.

I can't exactly say what they did because my wife picked up the car but apparently the timing is supposed to be at approximately 2 degrees and the timing on our Jetta was set at something like 0.2. I am guessing this is cam timing in relation to the crank specifically with regard to when the injectors are firing.

Well it's been 3 weeks and not only is the engine smoother than it has ever been but there is a noticeable power increase. Much more low-end grunt than it had before. Definitely something to have the dealer look at and if they have questions tell them to call Frank at Rey Reece VW in Portland, OR
 

lwg

Active member
Joined
Jan 16, 2003
Location
Portland, OR
TDI
2005.5 Jetta
AudiMatt said:
Took our Jetta in about 3 weeks ago after it has had 2 new dealer installed flywheels to try to fix the rough idle issue. They had a VW service Rep come and look at the car and I guess they did some chatting with a VW engineer. I guess they have encountered a couple of cars with the chronic rough idle (hmmm) and have discovered that on some cars the timing has either slipped or is not right from the get-go.

I can't exactly say what they did because my wife picked up the car but apparently the timing is supposed to be at approximately 2 degrees and the timing on our Jetta was set at something like 0.2. I am guessing this is cam timing in relation to the crank specifically with regard to when the injectors are firing.

Well it's been 3 weeks and not only is the engine smoother than it has ever been but there is a noticeable power increase. Much more low-end grunt than it had before. Definitely something to have the dealer look at and if they have questions tell them to call Frank at Rey Reece VW in Portland, OR
Score one for the team! Just moved to Portland and have been fighting this issue for a while. Already got a new Clutch and Flywheel from VW for it slipping at 20K. The rough idle has been driving me nuts. I'll give them a call and see what they can do about this.
 

oldpoopie

Vendor
Joined
May 14, 2001
Location
Portland Oregon
TDI
2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
Matt, thats awsome news. You've been battling this for a long time!
Welcome to PDX Larry.
-J
 

06SpiceRedTDI

Veteran Member
Joined
Jun 12, 2006
Location
Longview, WA
TDI
2006 Spice Red TDI Jetta, 2006.5 DSG Platinum Gray TDI
AudiMatt said:
Took our Jetta in about 3 weeks ago after it has had 2 new dealer installed flywheels to try to fix the rough idle issue. They had a VW service Rep come and look at the car and I guess they did some chatting with a VW engineer. I guess they have encountered a couple of cars with the chronic rough idle (hmmm) and have discovered that on some cars the timing has either slipped or is not right from the get-go.

I can't exactly say what they did because my wife picked up the car but apparently the timing is supposed to be at approximately 2 degrees and the timing on our Jetta was set at something like 0.2. I am guessing this is cam timing in relation to the crank specifically with regard to when the injectors are firing.

Well it's been 3 weeks and not only is the engine smoother than it has ever been but there is a noticeable power increase. Much more low-end grunt than it had before. Definitely something to have the dealer look at and if they have questions tell them to call Frank at Rey Reece VW in Portland, OR
I called Reece and scheduled an appointment with Frank. I sure hope he fixes my car as well. I have had the shakes at idle since 200 miles
 

fireice

Well-known member
Joined
Aug 29, 2005
TDI
Jetta, 2005.5 , blue
it will be great if somebody can outline what the timing solution was.

maybe then vw can issue a tsb and have our out-of-warranty cars checked/fixed for free..

i know- wishful thinking...

alex
 

AudiMatt

Well-known member
Joined
May 16, 2006
Location
Gresham, OR
TDI
2010 JSW TDi DSG
Hopefully Frank can fix a few people up. So far it has made a big difference in our car. Frank seems to actually care to make things right on the car and has really done a lot for us.
 

eli

Veteran Member
Joined
Oct 22, 2002
Location
I-95
TDI
2017 Cruze stickshift 2019 Terrain
first day above 50 degrees in a while, and the lumpy idle is back.
powering-on the rear defogger smooths it out, as before...
 
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