Polo gti 20vt boost problems HELP!!

[Phile6802]

Hi just bought a polo gti 20vt last week and I have noticed when driving hard especially in high gear the turbo is spooling up and down and up and Down some times it does it some times it boost fine any one had this before any help would be really great! Thank you In advance!

[GTi_Red]

Split pipe somewhere, PVC valve or diverter valve

[Phile6802]

Sorry not very mechanically minded? Like a boost leak and I have just googled the pcv valve it looks abit oily/damp is this normal it didn't look major just abit oily or is this probly the cause?

[Phile6802]

I have also just had my forged recirc valve in bits (007p) it all seems ok the the spring is not snapped or anything like that the only thing is when I have lookd at them on the Internet is there not supposed to be a washer in it aswel as the spring (yellow) and the other internal part?

[Simon90]

N75 valve?

Common to go on these engines

[Phile6802]

Yea been told there something to look out for but I was told by the sounds of the problem I have it's probly not that I plugged it into a snap on computer and Thers no faults HELP!!!

[TehSniper]

N75 or a dirty maf, get some cleaner and clean it out and see what happens

[ryanday91]

mine was doing this when i bought it, buy a brand new genuine n75 valve from vw! about 50 quid i think really easy to fit, drives like a new car now

[noone025]

Could be the tune, N75, sensor, valve, etc. Are you feeling it? The small K03 will only push hard up to 5k rpm, but what you describe is more of a ongoing fluctuation.

You might be best taking it to someone, find someone to help you log it (VAGCOM, etc) or finding someone with a Polo that you can swap the MAF and N75 with rather than fork out for new parts to replace components that are working fine.

You can try disconnecting the N75, you should get a flat 5-6psi, but you're not going to really know whats happening there without logging

[Phile6802]

Thanks for all the help people it was the n75 valve in the end I picks one up from a scrap yard for free it was off a tdi Octavia but is doing the job just fine I have ordered a tt 225 Quattro one aswel just for a spare thanks again