My car had been getting fairly persistent knock, always around 0.9 load, 1800-2000rpm, and generally around 0psi or just under. Usually the knock is between 1.4 and 2.8, but sometimes much higher.
I've been troubleshooting for the last couple of months... with much help from Matt (Kido) analysing the logs. So far I have done the following:
– car has been checked out for vaccuum leaks (a couple fixed)
- car has been checked out for exhaust leaks (a couple fixed)
- injectors have been replaced
- fuel pressure has been tested, and fuel pump visually inspected (o-rings re-seated)
- WG duty cycle set to zero for testing
– less timing in tune (made it worse)
None of the above has made any difference.
Anyway, Matt is pretty certain it is the wastegate actuator causing the flap to rattle (phantom knock). I have adjusted the pre-load of the wastegate actuator and this has definitely changed the knock. Now it happens at around 1.5 to 2.0 load, 2800rpm - 3500rpm, 5 to 10psi (not ideal... I'm avoiding boost until I figure out what is going on). The knock is also less than before (usually around 1.4 instead) I guess tightening the wastegate causes it to stay shut longer, and now it is opening at higher boosts. So I suspect maybe the noise happens when the wastegate is opening.
Does that sound like the correct theory? Or would have tightening the preload of the wastegate simply changed the dynamics of the boost tables...
Just trying to work out if I should be spending money on a new wastegate actuator or not
Here's a recent log file of when the knock occurs... http://www.datazap.me/u/cynner/logs-20- ... oom=77-119
Thoughts? Thanks!
Kim