vertigo
2007 NCV3 3500 3.0l
I've seen the admonishment in multiple threads never to separate the EGR Valve's servo motor assembly from the valve body, and that failure to heed this warning would be immediately fatal to the continued operability of the EGR assembly.
I can confirm that it is indeed possible and quite simple to reassemble the EGR after having removed the upper servo motor section of the EGR from the lower valve & body section, at least on my 2007 OM642 engine.
I initially made the same mistake as many others before me, removing the security screws and separating the servo motor when I was actually planning to remove the entire EGR assembly. Upon reinstallation, I immediately found my turbo boost and RPM limited (to about 2800rpm), and the ScangaugeII showed me a new P0404 TDC which would not clear.
To solve the problem, I disconnected the EGR wiring harness connection, again removed the 2 security screws on the EGR assembly, lifted off the EGR servo motor, rotated the motor shaft approximately 180 degrees, carefully verified that the plastic spider coupler was properly seated in the valve assembly, carefully reseated the servo motor into the spider coupler which required a slight rotation of the servo motor to align it for reinstallation of the security screws, reinstalled the security screws (including the metal bonding bar which seats under the right-side security screw and hooks under the metal housing of the top of the servo motor assembly), and reconnected the wiring harness.
Problem solved! After clearing the stored DTC codes with the scangauge, the P0404 DTC is no more! Now I can get back to diagnosing the lack of turbo boost that prompted me to mess with the EGR in the first place, but at least I don't have to buy a fancy new EGR valve assembly just to clear the P0404 code.
I can confirm that it is indeed possible and quite simple to reassemble the EGR after having removed the upper servo motor section of the EGR from the lower valve & body section, at least on my 2007 OM642 engine.
I initially made the same mistake as many others before me, removing the security screws and separating the servo motor when I was actually planning to remove the entire EGR assembly. Upon reinstallation, I immediately found my turbo boost and RPM limited (to about 2800rpm), and the ScangaugeII showed me a new P0404 TDC which would not clear.
To solve the problem, I disconnected the EGR wiring harness connection, again removed the 2 security screws on the EGR assembly, lifted off the EGR servo motor, rotated the motor shaft approximately 180 degrees, carefully verified that the plastic spider coupler was properly seated in the valve assembly, carefully reseated the servo motor into the spider coupler which required a slight rotation of the servo motor to align it for reinstallation of the security screws, reinstalled the security screws (including the metal bonding bar which seats under the right-side security screw and hooks under the metal housing of the top of the servo motor assembly), and reconnected the wiring harness.
Problem solved! After clearing the stored DTC codes with the scangauge, the P0404 DTC is no more! Now I can get back to diagnosing the lack of turbo boost that prompted me to mess with the EGR in the first place, but at least I don't have to buy a fancy new EGR valve assembly just to clear the P0404 code.
