Rough'ish' idle, stuttering/juddering when cold (with a newPCV)??

[Alex156]

07 GTI standard with 81k

Hi, i've searched various forums and found similar symptoms but nothing concrete.  To top this i've also had it into my local VW dealer and the problem still isn't sorted so I thought i'd have a go at describing my exact symtoms to see if anyone can offer some advice.  I plan on going back to the dealer but would like to have some opinions to guage their comeback with.  Brief description of problem/progress to date is as follows;

- Approx 6 months ago noticed slight juddering/stuttering under acceleration when cold (less than 90 on the water temp).  Typically only in high gear (5th/6th).
- Major service in August at main dealer, fault mentioned.  No change when getting car back but no issue identified by garage.
- Early Septmber, car revving on own at idle.  Back to main dealer (again mentioned juddering/stuttering).  Problem identified as faulty PCV valve.  PCV Valve replace which to be fair fixed revving problem but stuttering/juddering remains.
- Issue not getting any better and arguably slightly worse.  Starting to notice it in lower gears (but again, only when cold).  Car can be lumpy when idling and if you raise rpm to approx 2000rpm and hold it you can hear the odd 'pop' from the exhaust that sounds like something is missing?

I'd really appreciate any thoughts you may have as this niggle is starting to make me fall out of love with this car.  I would realy like to get to the bottom of it and get it sorted. 

Cheers

Alex

[56OctyVRS]

That sounds to me like either a spark plug or coil pack thats at fault. My bet would be the plugs.

[bacillus]

That sounds to me like either a spark plug or coil pack thats at fault. My bet would be the plugs.

I tend to agree as it could be a misfire but with a low enough count to not trigger a fault code.
Live logging with vcds show prove or disprove this hypothesis.

[Timi8888]

If it only happens when it's cold, it could be something to do with exhaust? I.e Cat convertor temp sensor lambda sensor?

[E30Dom]

My money is on spark plugs, when were they last changed?

[Alex156]

I've had it back to the main dealers since my original post. They has it for a week and still couldn't fix it. They tried:
- spark plugs
- coil packs
- low pressure fuel sensor
- some sort of loom to hpfp?
- fuel filter

They have said that as they can't find the fault and it's not showing on VAGCOM it's just a case of driving it until it gets worse. I'm thinking of selling the car as its really frustrating me. If anyone can shed any light on the issue I'd appreciate it?

[ttdan]

Sorry to Hi jack the thread but any anwsers to this may help 

I have a similar issue with my July 2007 ED30 51k miles.

Mine had the PCV replaced which fixed the revving on its own problem but still has a rough idle, very poor when cold (with a slight smell of fuel) feels like its running on 3 cylinders, improves when warm but its also inconsistent. If you wait long enough when idling, 30 seconds + the engine light will flash and then come on permanently. I have replaced no 4 cylinder coil pack as an experiment which made no difference. Plugs were all renewed last service about 5k miles ago. I suspect injector but it runs great and pulls like a train apart from this, the problem in this weather is grip!

A mate with VCDS checked for fault codes and this is what we found for the engine module, any ideas welcome.

Address 01: Engine        Labels: 06F-907-115-AXX.lbl
   Part No SW: 1K0 907 115 T    HW: 8P0 907 115 B
   Component: 2.0l R4/4V TFSI     0010  
   Revision: 5BH16---    Serial number: VWX7Z0G63NB8LJ
   Coding: 0403000318070060
   Shop #: WSC 01279 785 00200
   VCID: 37792FEF3FDD

4 Faults Found:
000768 - Random/Multiple Cylinder Misfire Detected
               P0300 - 001 - Upper Limit Exceeded
             Freeze Frame:
                    Fault Status: 01100001
                    Fault Priority: 2
                    Fault Frequency: 3
                    Mileage: 82149 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 14:52:21

             Freeze Frame:
                    RPM: 842 /min
                    Load: 18.8 %
                    Speed: 0.0 km/h
                    Temperature: 59.0∞C
                    Temperature: 30.0∞C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.097 V

000772 - Cylinder 4: Misfire Detected
               P0304 - 001 - Upper Limit Exceeded
             Freeze Frame:
                    Fault Status: 01100001
                    Fault Priority: 2
                    Fault Frequency: 3
                    Mileage: 82149 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 14:52:35

             Freeze Frame:
                    RPM: 845 /min
                    Load: 18.4 %
                    Speed: 0.0 km/h
                    Temperature: 59.0∞C
                    Temperature: 30.0∞C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 14.097 V

012555 - Low Pressure Fuel regulation: Fuel Pressure Outside Specification  
               P310B - 004 - No Signal/Communication - Intermittent
             Freeze Frame:
                    Fault Status: 00100100
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 82240 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 12:17:44

             Freeze Frame:
                    RPM: 866 /min
                    Load: 17.2 %
                    Speed: 0.0 km/h
                    Temperature: 81.0∞C
                    Temperature: 45.0∞C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 13.970 V

005634 - Power Supply Terminal 30: Voltage too Low
               P1602 - 002 - Lower Limit Exceeded - Intermittent
             Freeze Frame:
                    Fault Status: 00100010
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 0 km
                    Time Indication: 0

             Freeze Frame:
                    RPM: 0 /min
                    Load: 0.0 %
                    Speed: 0.0 km/h
                    Temperature: -40.0∞C
                    Temperature: -40.0∞C
                    Absolute Pres.: 0.0 mbar
                    Voltage: 0.000 V

Readiness: 0110 0101

[ttdan]

Just an update, no 4 injector replaced and all fixed.