TODAY’S TIMING FAILURES
Timing components are more complicated then ever. Today’s components were designed to last well over 100,000 miles, with proper maintenance. Sadly, often due to poor maintenance and falsely stated factory oil maintenance claims, many timing components are failing prematurely. The problem is, some do not know how to diagnosis what caused the failure in the first place, and are caught in a bad place when it fails again. — Oil pressure is the primary source of tension on these long OHC timing chains. This pressure is focused in the tensioner and it’s sliding piston that extents out to a rubbing block or arm that is designed to keep tension on that chain. The guides do just that, guide or offer a path for the chain to run. They are not on the pressure side of the rotation. — Broken guides are a sign of a tensioner problem. Guides do not break on their own. A lack of oil pressure causing a tensioner not to extent, or a tensioner that has contamination and cannot extend will allow the chain to go slack and whip around. This will indeed break guides. — New tensioners often get a bad wrap when there is a second failure, when it is usually caused by contamination and sludge in the old oil. If you tip your tensioner over and allow oil to drain out, you’ll see the sludge and particular matter that is fouling it up. The original failed for a reason and unless you remove that reason entirely from the crankcase, it will find it’s way into the new tensioner. — Further, some installers do not have the proper tools to do the job and simply some of them are just do not have the know how to properly install them due to the complexity of the timing system. Always follow the manufacturers torque spec for each of the tensioner bolts so as not to damage it, and always use the O.E.M. specified oil type and viscosity. Many late model vehicles spec synthetic oil and the performance of the system can be compromised if corners are cut and the wrong oil is installed.
Engine Pro Tech Committee
October, 2018
