My 01 ALH Golf has been going into limp mode and generating code 17965 - Charge Pressure Control: Positive Deviation Intermittent. So I read up on this problem, and think it may be the N75 valve. Here's what I found:
Turbo actuator/lever move when vacuum is applied via a Miti-Vac. Seems to move at the right vac levels, not entirely sure if I am getting full travel, as I was testing this with one hand on the actuator lever and one on the miti-vac. But it moves and holds pressure and position.
Overall Vac is OK not great (about 20in per the mitivac gauge). Think it might be my vac pump as it is getting old (~300K miles), but need to get a know accurate gauge to double check.
I pulled the N75 and am trying to test it, but am having difficulty in finding out what exactly it is supposed to do. When off the car no power to it, It seems the main vac and out lines are connected. But I can also blow into the relief port and get some but not full flow thru there too??? (all this testing by mouth so no extreme pressures here)
I was thinking the N75 should be a switch, the out port connected to either the vac port or the relief port 100% depending on power to it, none of this part way stuff. Is that right??? Seems like my N75 is leaking a bit between the relief and vac ports when no power is on it.
Does anyone know for sure what flow should and should not be with this valve?
TIA
Turbo actuator/lever move when vacuum is applied via a Miti-Vac. Seems to move at the right vac levels, not entirely sure if I am getting full travel, as I was testing this with one hand on the actuator lever and one on the miti-vac. But it moves and holds pressure and position.
Overall Vac is OK not great (about 20in per the mitivac gauge). Think it might be my vac pump as it is getting old (~300K miles), but need to get a know accurate gauge to double check.
I pulled the N75 and am trying to test it, but am having difficulty in finding out what exactly it is supposed to do. When off the car no power to it, It seems the main vac and out lines are connected. But I can also blow into the relief port and get some but not full flow thru there too??? (all this testing by mouth so no extreme pressures here)
I was thinking the N75 should be a switch, the out port connected to either the vac port or the relief port 100% depending on power to it, none of this part way stuff. Is that right??? Seems like my N75 is leaking a bit between the relief and vac ports when no power is on it.
Does anyone know for sure what flow should and should not be with this valve?
TIA