Zeng, P., Solferino, V., and Stickler, M., "Direct Injection Design Principles for Noise Vibration Harshness," SAE Technical Paper 2017-01-1052, 2017.
1Engine ticking noise is one of the key failure modes in today’s direct injection (DI) engines. High ticking noise results in high Things Gone Wrong (TGW) index, which negatively affects customer satisfaction. In this paper, the root cause of the ticking noise from DI injector in direct mounting will be presented. Design principle such as injector impact force to cylinder head and DI injector isolator design with 2 stage stiffness is proposed.