i know the standard n75 are prone to failing

would i hear anything if this is the case

im getting slight air noise when driving and sounds like its coming from n75 or dv

as when the air is released from the dv when foot comes of pedal sounds similar noise

sounds like its coming from same place

should i hear this

air going in and out? or could something be knackered

also its been remapped and had a forge 007p and has been ok but last 2 days dont feel the same

i.e only gets to around 55-58mph in 2nd was getting to 70ish

Edited 21 July, 201114 yr by lee1972

With a standard recirc valve when your car is remapped you will get more noise out of it as you're running more boost. The standard ones are crap and they can't really cope that well with the extra boost. As for the N75 are you getting boost spikes or is it boosting more like it should from a remap?

Standard DV is fine on remapped cars, but prone to seal failure when old. Remember the OEM DV fitted to the VRS is the same as fitted to 225bhp Audi's & Seat's so easily capable of handling a stage 1 remap. There's a load BS spread around about having to uprate the DV when remapping. The advantage of fitting Forge/Bailey/Turbosmart etc DV's is that generally don't fail, are serviceable, & can be adjusted or have heavier springs fitted etc for stage 2 etc.

N75 failure is pretty rare, but not unheard of. More likely that you have a split boost pipe or the DV seal has gone. Split boost/vacuum pipework is extremely common on all VAG 1.8T's, & can be hard to spot.

It's easy to test if your DV is working correctly by removing it pushing up the piston & holding your finger over the small top pipe. If the seal is ok the piston should stay up till you take your finger off the top, if it drops down before you take your finger off it's seal has gone.

havent got the standard dv

brought a 2nd hand forge007p off ebay

but sounds the same noise as when the air is released

havent got a clue how to check as had to get it fitted by someone on here