GM has had different timing mark designs on both the timing and balance shaft chains. Independent of GM’s designs, Cloyes has designated the timing marks as shown in the illustrations to the right. With all designs the unique timing mark is aligned with the intake balance shaft sprocket timing mark and intake cam sprocket timing mark.

GM Ecotec 2.0L/2.2L/2.4L I-4 Timing Tensioner

GM has had three different tensioner designs. The first design had a rubber O-­ring, had a larger tensioner piston, and was a two-piece design. The second remained the same except had no O-­ring. The third supersedes all previous tensioners, has no O-ring, has a smaller tensioner piston, and is one piece. This tensioner is shipped and installed deactivated and cannot be deactivated without disassembly. Tensioner is deactivated when the tensioner piston moves freely back and forth. Do not install activated.