Low boost 6lbs

[GTiGage]

so i completely new to this whole VW / turbo thing ... i just recently got the car its a 2002 GTi AWP engine the car has a FMIC and blow off valve, it ran great when i first got it was pushing 18-20 lbs of boost max and 14-16 normally. After driving the car for maybe 200 miles the car blew the hose between the turbo out pipe? and that aluminum chamber that looks like its there to just avoid the pulleys on the motor (is there a name for that hose?) when it did that it pushed 0 boost all the time. but i got the hose fixed with a new silicon hose wrapped in Kevlar but its now only pushing max to 6lbs? the car will also surge or jerk almost at 3k-5k unless you take it easy and slowly get into those rpms? i was thinking MAF? but i dont know if that would fix the boost problem. any help will be appreciated.

[Slimjimmn]

that hose originally is attached via a clip to the metal pipe. How did you attach a silicone hose?

[GTiGage]

i removed the clip from that hose and put it on the new one it wasn't to hard to do. but i think it still leaks a little its not as tight as it used to be. is there a place i could buy that hose?


i removed the n75 valve yesterday and it seemed to help it went back to pushing boost (18-20) again but i hooked it back up and back to 6lbs of boost so i'm guessing its bad.

[groggory]

Any hose that is attached to the turbo compressor outlet is considered a 'charge pipe'. This includes the hose that you talked about.

The flat pipe that is there to avoid the pulleys and such is referred to as the 'pancake pipe'.

Are you sure it has a blowoff valve? These cars do not like blowoff valves. We use a metered air system via the MAF (mass air flow sensor). The computer keeps track of how much air is in the system at any given time. If air escapes via a blow off valve your car will not perform as well as it would compared to you using a DV (diverter valve). A diverter valve reroutes charge air back into your intake air stream (post MAF).

If you're stuck at 6 PSI then the previous owner likely cranked the wastegate. You are in limp mode. Limp mode basically feeds no air to the wastegate actuator. This causes your turbo to run off the wastegate spring pressure that is stock 5 pounds. If you are running 6 PSI under limp mode that makes me think the previous owner increased pressure on the wastegate actuator. I'd suggest backing off the wastegate actuator rod a bit.

When you say you removed the N75, what do you mean exactly? There are three nipples on the N75. One goes to the intake, one to your charge pipe, one to the wastegate. If you removed it you'd have 3 hoses that were disconnected. Or do you mean you electrically disconnected it.

Do you have access to a vag com?

[GTiGage]

i dont know any one with a vag com. i removed the two lines off the n75 and left it electronically connected still, and yes im sure its a BOV ive been meaning to get a DV for it but i want to get it running better first i dont think its in limp mode though is there a way to tell?

[DMVDUB]

Just adding to what groggory said, the ecu can use other means to put you into limp other than controlling the n75. It can release boost through the DV or BOV by means of the n249 if you haven't done the delete. It can also shut the throttle body on DBW cars, as well as retard timing. Find out why it's going limp, because if it really doesn't like something it WILL find a way into limp mode. Annoying but there so you don't destroy something.

[Slimjimmn]

BOV will cause limp mode, if you cant keep it closed at idle.

[GTiGage]

im pretty sure its closed at idle and like i said it ran great untill that boost leak once i fixed the boost leak is when it started acting like this i didnt mess with anything but fix that hose so why would my bov be a problem now? thats the only reason im thinking its a sensor or something because it runs fine when i unhook the n75 like i stated before

[groggory]

You need access to a vag com

Otherwise we'll throw dozens of ideas your way

[GTiGage]

how can i get one?

[Slimjimmn]

there is no aftermarket hose that fits the clip style pipe in awp engines. You have to either:
1-convert it to old agu 1.8t from a beetle auto or 1.8t auto
2-convert it with eurojet kit
3-go FMIC setup.

you cant just get a hose and slide it over the old pipe.

[GTiGage]

it has fmic. the hose with the metal clip that holds it in has been replaced

[zrau17]

MAP sensor?