Loss in Power, Advice needed.

[keyser]

Ok folks, not sure where to start.  Before I begin I must state my mechanical knowledge is very poor so bear with me.

I have an 05 Standard GTi.  About 5 months ago the top cover of the air intake unclipped itself and created a rattle in the engine when it vibrated.  Only realised what the rattle was after about 2 weeks of searching. Clipped it back on. Anyway, remapped the engine in May with Torquetronix in Northern Ireland.  Absolutely thrilled, a completely different car.  At the beginning of July I opened the bonnet to put in windscreen fluid and notice the top of the air intake had come off again, this time it had completely unclipped itself and was just sitting in the engine bay.  I clipped it back on (in hindsight I should have got a new one).  About 2 weeks later I was driving on the motorway.  Put the shoe down a bit and heard a sudden noice from the engine bay and a loss in power.  Almost no turbo at all. Pulled in and noticed that the intake cover and come off and was nowhere to be seen. 

I took it back to the remap guy who tested it and says the remap is fine but the turbo is only boosting at 0.4 bar.  He checked the air intake.  I had the car serviced yesterday ( out of warranty so a home job by a friend who is one of the chief mechanics at a vw dealer).  He also ran diagnostic checks and said everything was fine.  The car now drives almost as standard. Definately better than when I took it back to the remap guy but not what is was. But when I open the window and engage the turbo, the sound coming from it doesn't sound the same.  Not sure how to describe it but a longer hiss and not as loud.

Really p***ed off at the moment.  I'd really appreciate your thoughts.  If anyone knows some vw specialists in Northern Ireland that would be a help.

[RedRobin]

....Possibly your Diverter Valve has blown, especially as your boost is down and loss of power is typical with the issue.

On a remapped GTI it's a wise preventative measure to change it to a Forge DV - The stock DV's are known to be a weak link, especially on VW builds which have the DV located near the turbo.

[Hurdy]

I'd agree with RR, sounds like either the DV is blown or you have a leak somewhere else. Joesgti had the issue with a leak and his sounded like your description. He too ran a rolling road at standard output 200bhp as he was remapped, but should have been much higher.

[keyser]

Thanks fellas.  I'll PM joesgti and see what he thinks.

[gazbutmk5gti]

DV all day long

[MAT ed30]

defo the dv

[adw555]

Hey keyser,

I also have an out-of-warranty 05 GTI over here in NI. Can you recommend anyone to service it? Really don't want to take it back to the stealer...each time they had it there were issues with the work they did...tried 3 different VW dealers over here as well.. :-(

[keyser]

Hi ADW

The guy I took it to was a friend of a friend type of thing.  I'll not mention any names but he is a mechanic at one of the dealers. He doesn't really make a practice of doing homers, more so a favour.  To be honest though I was a bit disappointed that he didn't sort the turbo so I'm in the same position as you, looking for a good independent.  Apparantly there is a good place in Coleraine that my brother mentioned.  Don't have any names yet but will check this week and let you know if I find anything.

[vRStu]

Buy yourself a new diverter anyway before you take it to be checked, give it to the tech and tell him to swap out the old one.

A new DV is less than £30 which will be less than the labour charge to swap it out again after you've realised the current one is fecked and you've been and bought one.

PN is 06F 145 710 G

Once you've changed the DV and ruled that out then things get a little more difficult.  You'll be wanting to get hold of VAG-COM and checking N75 duty etc.

[keyser]

Is the diverter valve or dv known under any other name?  I have rang about 4 different garages, including 2 vw dealers in Northern Ireland and none have heard of either.