Ongoing limp mode

[Sunny43.5]

2004 T5 2.5 turbo Tiptronic , okay have been battling with my conscience on this one as we want to sell the van and I wont be happy until I can get this sorted . After all the debacle with the auto and then the Turbo we still have an ongoing problem which is eluding an answer . First start up in the morning is fine but when I back out of the drive and then engage drive to go uphill the van takes around 30 metres before the turbo kicks in and it takes off like a scalded cat . After that it is fine , now the main problem I am faced with is when out the highway driving at 100 kmh on flat ground all is fine BUT every now and then it seems when I go to accelerate just a small amount the van seems to bog down and then the dreaded LIMP mode kicks in . I have changed the N97 valve I think that's the one and also the MAP sensor again might be wrong name and also fixed a split in the vacuum line which was a major problem when the Turbo was replaced by a supposed reputable engine shop . So my question is can the van be diagnosed with the appropriate software to find what is causing it to go to limp . The first series of times it happened I had been told by Jmac that it was overboosting ?? so the above things were done to hopefully eliminate that but seems that it is still a problem . Can the diagnostics do a deeper scan to pinpoint what is causing it , Jmac only showed me the fault code and cleared the memory . Turning it of and on clears the limp but it would be a bit hard to sell it like this . Thanks in advance for any suggestions . Howard

[The One]

Whats the fault code mate?

[Umai Naa!!]

Overboost is usually sticking VTG flaps in the turbo, or a worn wastegate.

Re-scan it anyway and go from there. Clearing it won't fix the problem, only the symptoms. Needs actual diagnostic time spent on it.

[Sunny43.5]

Thanks Umai I just hope I can get someone up here to give me a truthful answer , I just don't like many trust the VW people to give a straight answer , the last time it was at VW dealer many years ago they told me the original Turbo was leaking oil so I ask how much to fix reply ? oh around $6000 plus . These people seem to think we pay a premium for their technology and that we should then be expected to pay a premium for something that I am sure could have been repaired by a mechanic , trouble is these days they are not mechanics they are technicians and if the computer cant fix it then they take the easy road and just bolt on a new part .

Sorry I forgot to mention when Jmac scanned and it told me it was overboosting I replaced the Turbo with a working Turbo from another van it was at the time still performing normally , the place that fitted it did a complete clean and inspection before fitting . I fitted those parts mentioned after the turbo was fitted .

[Sunny43.5]

Whats the fault code mate?

All I remember from last scan was it was overboosting I did not get an actual number if that's what you mean .

[Snail Style]

Probably a good idea to make sure all the vacuum lines are routed correctly.