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Discussion Starter #1 (Edited)
Just got the van back from the garage after the gearbox went kaput and on the way home I noticed the van not pulling very well. Before it went in the garage all was well with the turbo boost, It normally boosts up to 11-12 bar but wont go past 4-5bar now.

Im thinking it may be the MAF sensor but im going to get it on a ramp tomorrow to see if all the pipes etc are in the right place. Does anybody else have any other bright ideasA: Ive looked through relevant threads and ive still got a few more to read.

Ive just had the gearbox reconditioned and a new clutch / flywheel and thrust bearing fitted, are any of these potentially to blame!!
 

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Hi Jon,

You are on the right lines checking the pipework etc.

If its only happened since the vans been worked on there is a strong chance the
the boost issue is as a consequence of something they did inadvertantly.

If the pipes are all ok and fitted tightly then it might be time to start looking at MAF, N75 etc but a fault
scan might help lead you in the right direction.

Regards.

Ron.
 

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Check electrical connection to intercooler. Same symptoms as Bens van 2 second fix.
 

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Discussion Starter #4 (Edited)
Cheers for the replies lads.

I ran Vagcom tonight and had no fault codes so I got down to looking for the fault on the turbo. I found no pipes missing and all was in the right place and tight apart from one solid plastic pipe connection to the turbo.

The plastic pipe coming in from the left of the turbo comes from the air filter via the MAF sensor, this seems to be rather loose at the turbo. There are no clips used to fit this part apart from an O ring push fit seal on the turbo.





Theres quite a lot of play in this joint but it doesnt look to deformed or melted, is this my problem? I also noticed quite a lot of oil leakage from this area.

Any thoughts will be gratefully receivedT:
 

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i took the engine out of my 2.5 tdi ajt. when i refitted the turbo wouldn't kick in. i drove it like that for almost a year. 2 weeks ago i checked the hoses from the n75 and i'd put the air intake and the turbo hose the wrong way around, swaped them back and all is now good. mat be worth checking for damage too, only costs 3.50 fo silicone replacements...T:
 

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Behind the coolant expansion tank,its the squarish one thats hard to get to.The other two valves control EGR and anti shudder valve,you might have to remove these to get to the N75 beneath. Make a note of where the thin tubes belong before you pull any off.
 

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ive stuck a jubilie clip arround that pipe you have thats loose (the one from the intake), i think they just expand with time and even a new o ring wont get rid of the problem T:
 

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Discussion Starter #11
Thanks for the replies people. Im taking it back to the garage today for them to have a look, then if they cant fix it its back to our self diagnose attempts. And yes looking at my boost gauge it is PSI no Bar sorry.
 

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I have the same problem with this plastic pipe being loss, would it make any difference to the vans performance ? please keep us update with what if any thing the garage come back with ?

BR

Jon
 

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Discussion Starter #14
Had a good look about today and all seems well with the pipes going to the turbo, I replaced the worn plastic pipe which fits perfectly, I also replaced the MAF and fitted a new air filter and made sure all the connections were good. Took it for a drive and its seems to be getting worse.

Boost has dropped away more (4psi) and it drives like a pig, the turbo dosent seem to be sucking air in as normally I can hear my K and N filter induction kit weezing. Im thinking my turbo is broken any thoughts!!.
 

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Discussion Starter #15
Ok the vans back from the VW garage in Newcastle and its running extremely sweetly. After an hours diagnostics by the fitter he found a missing bolt on the actuator and also other loose parts on the turbo, a bolt and a bit of spannering later and alls fixed.

The van is boosting well at 12-13psi and pulling like a train, the new MAF sensor, turbo pipes and air filter have helped as well. I only got charged for one hours diagnostics at a main VW dealership in Newcastle, so very happy as I thought the turbo was trashed and I thought it was going to cost me a fortune.A:
 
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