Date of Award


Publication Type

Doctoral Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering

First Advisor

Reif, Z. F.,


Engineering, Automotive.




A study was undertaken to determine the feasibility of developing an engine dynamic signal monitoring and diagnostic system for use on-line in a high volume engine manufacturing plant as well as in a research environment for the development of new engine components. The system will enable rapid and precise diagnostics of the production engine for identifying and locating manufacturing or assembly defects which do not include thermodynamics, combustion/or emission related defects. Recently published literature on engine noise and vibration monitoring and diagnostic systems is reviewed with special emphasis on the use of noise and vibration for on-line monitoring and diagnosing. A complete bibliography of 175 references is appended, together with the summary chart outlining the subject classified by topics. The feasibility of using noise and vibration for the detection of engine manufacturing and assembly defects as well as evaluating the effectiveness of component design changes, was originally carried out in the dynamometer laboratory. Here, customer returned engines were evaluated for noise and vibration using three different monitoring systems developed for the same purposes. In these systems accelerometers, microphones and pressure transducers were used in conjunction with both a conventional dynamic signal analyzer and a specially designed eight channel data acquisition system coupled with custom designed computer programs. All these systems are capable of detecting defects in customer returned engines. Detail reviews were carried out emphasizing the advantages and disadvantages of each system. The noise and vibration measurements were then correlated with actual manufacturing and assembly defects. The systems were also tested for evaluating the noise and vibration characteristics of changes in piston design. With the success in diagnosing customer returned engines, a field study was undertaken to determine the feasibility of using noise and vibration for detecting missing connecting rod bearings, loose connecting rod nuts, and other related manufacturing/assembly defects. A modified monitoring system which includes accelerometers and microphones together with a uniquely designed data acquisition system was used to obtain the noise and vibration data. In the initial phase, data was collected from fifteen partially completed engines having different defects. These were then analyzed to set the vibration limits for rejection. The on-line engine monitoring and diagnostic system was implemented and it was observed that in the test of more than 120,000 engines, the success rate in reduction of defective engines was 100 percent. Thus it was concluded that the monitoring system with a specially designed data acquisition system is capable of on-line monitoring and rapid and precise diagnosing of production engines with manufacturing and/or assembly defects. The system is also well suited for use in evaluating the noise and vibration characteristics of any engine when one or more of its components has undergone design changes.Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .T565. Source: Dissertation Abstracts International, Volume: 54-09, Section: B, page: 4798. Adviser: Z. F. Reif. Thesis (Ph.D.)--University of Windsor (Canada), 1993.