S3 boost Problem??

[GAZMAN]

Hi all recently just bought an s3 and it has a revo remap miltek exhaust, k&n panel filter and a forge 007, iv noticed the boost is kinda all over the place on it, one minute it feels like its pulling fine When u floor it 1st,2nd seem fine them 3rd onwards after about 4000rpm up the boost seems to have faded away like a flat spot then the odd time around 5000-5200rpm it would kick back in again.... i got it a full service today but still seems to be doing it, ma pal went all over it today for boost leaks etc but everything seemed fine, dont get me wrong sometimes it boosts fine all the way up n it pulls amazingly so i notice it right away wen it starts acting up, ma pal also plugged it into the comp no fault codes, anyone got any ideas? thanks, Gaz

 

[lnewland]

faulty n75??

 

[audicruiser]

Faulty N249? You need someone with Vag Com to do some logging while you drive it...

 

[marc33]

sounds like n75 mate. just had to replace mine as it was doing same thing but car running like a dream now ive changed it!

 

[dplovin]

as above mate

 

[m8arx]

Gary ive got an old n75 valve here if you want to try it. I bought new one thinking mine had a wee problem too but turns out mine was fine anyway.

 

[m8arx]

Faulty N249? You need someone with Vag Com to do some logging while you drive it...

love posts like this, log what exactly and then how do you know what your looking for? I.e. Whats right and whats not?

 

[Dani_B19]

Unplug your maf (mass air flow sensor, the thing that contects to your airbox with the plug in it), take it for a spin and see if it goes away?

 

[s3dave]

Log 118 it sounds like your fuel pump may be tired, although you would expect a fault..

 

[GAZMAN]

Well i changed the n75 still the same boost was on and off then unplugged the air flow meter.....spot on boostin all the way through the rev range so new one on order will be here tomorrow thanks guys

 

[audicruiser]

love posts like this, log what exactly and then how do you know what your looking for? I.e. Whats right and whats not?

If you know what a N249 and a N75 does, you will know what to look for....

 

[audicruiser]

Well i changed the n75 still the same boost was on and off then unplugged the air flow meter.....spot on boostin all the way through the rev range so new one on order will be here tomorrow thanks guys

Job done then Gazman!

 

[R1KVX]

i've got the same problem, just swapped my standard n75 valve with my mates ecs n75 off his cupra r, much better going to just replace it with a standard one from audi though

 

[Buzzer]

I had the same problem, got a smoke test done and 2 hoses
Had cracks in them , sorted.