View Full Version : on going boost problem.. help!

06-06-2009, 06:21 AM
well I still havent figured my car out it seems to be a mystery it is basically an all stock 1998 1.8t quattro 5spd with 75k on it. I changed the DV to a 710 and just installed a N75 f. On a 1.1 bar flash it was only spiking 11psi then dropping. There is no boost leaks. When I unplugged the n75 to the wastegate and took it around the block it would hit 16psi. Is there a way to test the signals to the N75 of do you think my wastegate or turbo needs rebuilt? any suggestions would help

06-06-2009, 06:39 AM
wastegate may not be actuating correctly... Who the chip manufactured by?

06-06-2009, 06:48 AM
if you unplugged the n75 and you only hit 16psi and it was floored then either you have a boost leak or your actuator is bad because without the n75 being connected the wastegate should have never opened and if you were flooring it the boost should have just kept building till you broke something in your engine which is why you never unplug your n75 and go WOT you have to only go part throttle.

06-06-2009, 08:38 AM
i would definetly say wastegate or clogged cat or even maybe the throttle body isnt opening all the way

06-06-2009, 06:16 PM
Chip is manufactured by speedtuning, and i only floored it til i got to 16psi and was scared to go any further. I believe that my wastegate may be biting the dust. Any one have experience with just replacing the wastegate? should it open around 7 psi?

06-06-2009, 06:19 PM
if the n75 is not plugged in then the wastegate should NOT open at any psi. the n75 tells the wastegate when to open

06-06-2009, 06:45 PM
I meant when just hooking up a compressor hose to the wastegate while the car isnt running

06-06-2009, 10:17 PM
By doing the test and getting to 16 psi you have just ruled the wastegate out. The wastegate is holding exhaust pressure properly. It still could be the actuator/spring that is actuating too easily. Other possible causes are faulty N75, a problem with the atmospheric input to the N75, or an issue with the ECU.

06-07-2009, 06:00 AM
yea im begining to think it has something to do with the wastegate (spring, flap), I believe it is actuating to early and there is also a rattle coming form the wastegate i believe.

06-07-2009, 07:36 AM
There is actually an adjustment on the actuator where it atatches to the wastegate arm. Perhaps it is not holding it tight enough in the closed position?. Rattling isn't good though.

06-07-2009, 01:28 PM
can you adjust WG actuator arm w/o taking the turbo out???

06-07-2009, 05:46 PM
I dont believe you can adjust while its on, i am going to rebuild my turbo and replace the wastegate as soon as I get all the parts.