Troubleshoot a Timing Chain Tensioner Test Bench

We are a manufacturer of automobile timing chain tensioners, based in Shanghai. The tensioners operate with a hydraulic damping mechanism to uniformly and consistently provide a specific force on the chain so that it remains tight. Engine oil enters the tensioner cylinder through a valve to push the non retractable piston against the chain. The object of a vibration test is to measure the magnitude and consistency of tension force provided by the tensioner when subjected to the conditions in which it is expected to perform in the engine environment. We will share the specific variables with the successful Freelancer. We have recently built a test bench to perform a vibration test on a range of different tensioners we produce. The test bench has been partially successful in that it is able to deliver the right sort of data we need. However, we have not been successful in getting the test bench to deliver consistently meaningful results. Upon starting the test, an initial data output range is recorded. This data range persists for about 20 minutes. After about 20 minutes of continuous operation, the data range succeeds to a new (much higher) plateau. We believe that the second plateau range is the correct performance range. We want to adjust our test bench design and/or method so that a consistent data output range is achieved upon start-up. Data output is derived from two force sensors which record the vibration force and speed applied to the piston-end of the tensioner, and the opposite force applied by the tensioner piston. Vibration is generated by rotation translated into linear actuation via a variable mechanism. Hydraulic pressure is delivered by an oil-pump system. Data is recorded and displayed by a software programme. Our proposed Project Milestones: 1) 10% upon an initial review and feedback of the test bench (design, data output, video) 2) 30% upon receipt of design/method change advice 3) 60% upon successful testing Schematics, photos, video, Skype/QQ/WeChat will be used throughout the engagement.