An aftermarket replacement Valve Cover for OE part number 11 12 7 552 281, sold by company noted as OTHER, was reviewed using the tools, measurement equipment and quality verification processes in use at APA Industries. This report itemizes non-conformances found with the OTHER Valve Cover when compared to cover 11 12 7 552 281 from the original equipment manufacturer (OEM). The notable issues are as follows:
The OTHER valve cover was attempted to be installed on the OE Engine Head Shown in Figure 1. Installation was attempted by 4 other members of the engineering staff with the same result. The OTHER Valve cover does not fit the OE Engine Head properly. The installation attempts revealed 2 bolts that could not achieve proper fit and torque, shown in Figure 2 and Figure 3.
OTHER valve cover seated on OE Engine Head without fasteners
Electric impact tool achieved specified torque, yet gasket was not compressed due to sleeve stand off.
Fastener sleeve ID is smaller than OD of locating feature on engine head.
Female fastener sleeve could not accommodate male locating feature.
Valve cover without bolt or sleeve. Housing must be forcibly deformed by installer to align fastener holes.
NG Part Fit Detail: bolt did not achieve specified torque due to part dimensions. Valve Cover hole location creates a NG bolt angle (in red), which did not allow the fastener to be installed to proper torque.
The press-fit fasteners were removed and the hole locations were measured using the FARO Arm, and then related to the corresponding location on the Engine Head.
Applying a positional tolerance on each point of ± 1.0mm, the OTHER valve cover has 17 out of 22 holes with a NG hole position in either the x-direction, y-direction, or both.
Additionally, the holes on the left side of the image, holes 18, 19 and 1, are off location in the X negative direction. The holes on the right side of the image, holes 11, 10, 9 and 8, are off position in the X positive direction. This is an additive situation. If you install a bolt into one end of the valve cover, all of the error is pushed to the other end of the part, causing the NG install experienced during the part fit activity.