# rough idle, tried everything



## 03_Jetta_awp (Jan 22, 2008)

Car is a 2007 gli dsg. It has a rough idle and the idle gets worst when it is in park of neutral. Ive already had my intake valves cleaned, spark plugs changed, pcv valve replaced with latest revision, fuel filter changed. I brought the car to the dealer and they told me that they cant find anything wrong with the vehicle because there is no code even though they felt the rough idle.
Dont know what else to check 

any help would be greatly appreciated


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## albinorineo (Feb 25, 2012)

Does the idle correspond with what the tac displays (I.E. does the idle hold steady on the tac or jump around with the feeling?)? Have you checked the mounts recently? When was the last time the DSG was serviced? 

Check the mounts(under battery tray and pendulum((Dogbone)))? Check DSG fluid. 

My '07 GTI has a slight vibration, but the tac is steady, so I just consider it part of the cars character, that slight vibration is subjective however, and I can see how it can feel like a rough idle.


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## 03_Jetta_awp (Jan 22, 2008)

the tach is steatdy but i can clearly feel the car vibrating, the tach doesnt jump around with the feeling, however its not a constant vibration, it feels as though the car is misfiring only in park and neutral. I havent checked the motor mounts, i checked the dogbone mount and its ok.


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## BlueDevil504 (Jan 19, 2012)

It could be a small boost leak. I had some rough idle as well, turned out it was a screw loose holding down the map sensor on the throttle body pipe. Just saying it could be something as small as a screw loose. Hope you figure it out


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## dmorrow (Jun 9, 2000)

Is the rough idle only when it is cold or all the time?


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## 03_Jetta_awp (Jan 22, 2008)

Only when its warm, although i just brought my car to vw because the dsg was making clicking noises from 5-4 and 3-2. Turns out something is loose or warped with the clutch packs, so there ordering me new ones which they said could be causing my erratic idle in N or P as well. They also checked all the mounts and cv joints and they were fine. Hopefully this resolves my issue.


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## carvelli63 (May 15, 2011)

*rough idle*

its not gonna be a boost leak if hes sitting in park or neutral. sounds like a vac leak to me. they're not always easy to track down though. vac pressure is highest at idle. id search for that. best of luck :thumbup:


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## StuMacLean (Aug 9, 2003)

Sounds like it's your coil packs. Sometimes when it's a little damp outside, or for no reason at all they will work intermittently at idle. My car would have a quite noticeable shudder when I was idling in traffic. 

If you have vag com look at the measuring blocks for each cylinders misfire counter. It might not be conclusive, but it's possible you could find out which cylinder is bad and only replace that coil pack. However if you're going to the trouble to replace them you might just want to replace them all. 

I've gotten to the point where I keep a spare coil pack in the trunk. I had one completely go on me a few years ago and I had to get towed in. It's such a simple swap you can do it on the side of the road with almost no tools. 

Best of luck! :beer:


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## Sandman333 (Oct 28, 2002)

I have the same symptoms. Runs fine when the engine is cold, but occasional misfire when in neutral (2008 Passat 2.0T (BPY) 6MT. 66K miles. It was worse in cold weather. 

Just the other day I started getting a total drop out of one of the cylinders after the O2 sensors were warm enough to go into closed loop mode and at WOT with boost over 17PSI (APR Stage I tuned since new). No doubt about it, one of the cylinders went completely dead in those conditions. Flashing CEL and then it set steady. 

I changed spark plugs today and that got rid of most of the problem. Instead of completely losing the cylinder, I get only 1 misfire per second or so under the WOT/Max boost conditions now. It's a very significant difference but it's still not fixed. I think the new plugs are a little easier to fire than the old plugs and it is masking a coil that is on the way out. I'm going to order new coils but I need a part number for the latest version. Anyone?


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## darkhalcyon (Oct 2, 2003)

Here's the one's I used:

http://www.ecstuning.com/Volkswagen-Jetta_V--2.0T/Engine/Ignition/ES2065380/


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## 64Bettle (Apr 24, 2011)

bump


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## bripab007 (Jul 7, 2006)

Check to see if your MAP sensor is gummed up with oil blow-by. Try cleaning it with electronics cleaner spray and some compressed air.


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## Sandman333 (Oct 28, 2002)

Sandman333 said:


> I have the same symptoms. Runs fine when the engine is cold, but occasional misfire when in neutral (2008 Passat 2.0T (BPY) 6MT. 66K miles. It was worse in cold weather.
> 
> Just the other day I started getting a total drop out of one of the cylinders after the O2 sensors were warm enough to go into closed loop mode and at WOT with boost over 17PSI (APR Stage I tuned since new). No doubt about it, one of the cylinders went completely dead in those conditions. Flashing CEL and then it set steady.
> 
> I changed spark plugs today and that got rid of most of the problem. Instead of completely losing the cylinder, I get only 1 misfire per second or so under the WOT/Max boost conditions now. It's a very significant difference but it's still not fixed. I think the new plugs are a little easier to fire than the old plugs and it is masking a coil that is on the way out. I'm going to order new coils but I need a part number for the latest version. Anyone?


 New ignition.coils fixed my problem. Less than $16 each from www.1stvwparts.com

Sent from my DROID RAZR using Tapatalk 2


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