john-wingnut
Active Member
Im currently trying to troubleshoot my annoying rhythmic ticking sound from the valve cluster in the engine bay.
Now im currently under the following impression, correct me if im wrong though:
The N75 valve shouldn't / doesnt make a tick sound, as it recieves pressure inputs from before the MAF and from the turbo which changes a variable valve to regulate the pressure sent to the turbo wastgate actuator, which is done by square wave oscillations from the ECU.
The N18 does tick on and off to control the vacuum applied to the EGR.
Now at idling neither of the above should be active, as there is no boost so the N75 is open, to keep waste gate shut and the EGR should not operate until engine warm or at higher revs as dirty air will choke the engine.
Now the ECU controls both of these valves, but must have a sensor for each i.e boost sensor to control N75.
But what does it use to determine when the N18 valve should be operated??
as this must be what is causing mine to sponaneously operate / tick when it shouldnt be
John
Now im currently under the following impression, correct me if im wrong though:
The N75 valve shouldn't / doesnt make a tick sound, as it recieves pressure inputs from before the MAF and from the turbo which changes a variable valve to regulate the pressure sent to the turbo wastgate actuator, which is done by square wave oscillations from the ECU.
The N18 does tick on and off to control the vacuum applied to the EGR.
Now at idling neither of the above should be active, as there is no boost so the N75 is open, to keep waste gate shut and the EGR should not operate until engine warm or at higher revs as dirty air will choke the engine.
Now the ECU controls both of these valves, but must have a sensor for each i.e boost sensor to control N75.
But what does it use to determine when the N18 valve should be operated??
as this must be what is causing mine to sponaneously operate / tick when it shouldnt be
John