Boost issues - assistance with new car purchase

[xjay1337]

So I've been looking at GTI's to replace my TDI with and I've found one which I went and looked at today.

Drove nicely, felt really tight, gearbox was spot on.
On the drive we did a full power through second and into third. It pulled "okay" shall we say. I'm used to loads of torque (from my diesel) so felt slow but didn't think "hmm something's broken". Engine sounded ok and no obvious signs of anything wrong, no weird noises or anything.


For reference the cars actual mileage when I scanned it was ; 124620km/77435miles. This was verified on the ECU as well. The car had been very recently serviced including the timing belt.  

The KM readings show that two of the codes happened around 300kms ago, and the other around 1500km previously.



I did a full VCDS scan and got the following (engine faults). I have done some research and checked on RossTech, but getting varying information from forums in regards to the problems.

Address 01: Engine        Labels: 06F-907-115-AXX.lbl
   Part No SW: 1K0 907 115 J    HW: 8P0 907 115 B
   Component: 2.0l R4/4V TFSI     0030  
   Revision: --H14---    Serial number: VWZ7Z0F8109248
   Coding: 040300031C070160
   Shop #: WSC 00326 210 71535
   VCID: 2D5B176DB40A1F1

3 Faults Found:
000568 - Manifold Pressure / Boost Sensor (G31)
               P0238 - 001 - Signal too High
             Freeze Frame:
                    Fault Status: 01100001
                    Fault Priority: 0
                    Fault Frequency: 3
                    Mileage: 121648 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 09:11:14

             Freeze Frame:
                    RPM: 1123 /min
                    Load: 16.1 %
                    Speed: 8.0 km/h
                    Temperature: 87.0°C
                    Temperature: 35.0°C
                    Absolute Pres.: 1020.0 mbar
                    Voltage: 13.970 V

000564 - Boost Pressure Regulation
               P0234 - 001 - Limit Exceeded (Overboost Condition)
             Freeze Frame:
                    Fault Status: 01100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 124380 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 13:00:53

             Freeze Frame:
                    RPM: 0 /min
                    Load: 0.0 %
                    Speed: 0.0 km/h
                    Temperature: 87.0°C
                    Temperature: 32.0°C
                    Absolute Pres.: 1020.0 mbar
                    Voltage: 12.446 V

000566 - Manifold Pressure / Boost Sensor (G31)
               P0236 - 008 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01101000
                    Fault Priority: 0
                    Fault Frequency: 1
                    Mileage: 124380 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 13:03:49

             Freeze Frame:
                    RPM: 0 /min
                    Load: 0.0 %
                    Speed: 0.0 km/h
                    Temperature: 84.0°C
                    Temperature: 36.0°C
                    Absolute Pres.: 1020.0 mbar
                    Voltage: 12.192 V

Readiness: 0000 0000



How can you have an overboost condition with the engine (presumably as the freeze frame is showing 0rpm) off?

I also did some logging, measured block 115 - not as much logging as I wanted, but I did a full throttle second run, not third as there was not the room and I had already gotten lost..


Column C is engine revs.
Column D is engine load %
Column E is Boost Pressure (SPECIFIED)
Column F is Boost Pressure (ACTUAL).

I logged using turbo mode so not sure if that caused it to read as actual boost showing as 2680, or whether this was a glitch or whether this would point to a fault MAP sensor? And cause the above error codes as it refers to signal too high it seems..


Screen grab of the logging is as below.

If someone could tell me if the problems are easy fixes, glitches in terms of perhaps random codes that just appear, or if I should avoid this car then the assistance would be appreciated.

[rich golf gti mk5]

I'm having over boost problems at min ill inform u if we sort the problem. Have u tred the n75 valve( module) that's next on my list

[edd666999]

I'd steer clear. Either get them to fix it before you buy or leave it.

[GTI-Pirelli]

I would say DV or associated fault.

When I first replaced my DV with the Forge one, I got exactly the same faults.
The connecting wire from the VW loom to the Forge DV fell apart (poorly crimped repair wires). Now soldered and heat-shrunk - as they should have been.
This stops the actuation that dumps the pressure when you let go of the throttle.
If the diverter valve doesn't open when you let go of the throttle, the back pressure on the turbo gets too high (no fuel into cylinder so no air required) hence Manifold pressure too high/over-boost condition.

I'd stay clear if you don't know how long it has been doing it. It puts a lot of strain on the blades of the turbo if you nail it and the pressure has nowhere to go. On the other hand if you like buying turbos... 

[xjay1337]

Thanks guys for the assistance.
Mr Pirelli thanks for your explanation :)

I will leave it in that case. Especially with the faults, in addition to that the owners are very strongly refusing to budge on price. I can find the same spec for less money, I wouldn't mind paying the premium but with the faults.. just not worth it.

[ROH ECHT]

Bad boost/MAP sensor...