Hello I’m Derek , I have 27 years as a professional mechanic/technician under my belt. I’m currently self employed as a mobile mechanic performing service calls and on site repairs. I have found forums like this one to be invaluable. Current conundrum is the notorious GM 3.6L Alloytech LY7 High Feature DI engine in a 2007 Saturn Outlook XE . Originally diagnosed by TDC’* P0017 P0018 P0019 and codes for random cylinder misfire. One or more of the timing chains stretched. I performed the repairs using an aftermarket timing chain kit consisting of the three chains, the three tensioners and gaskets, and the guides. Kit did not include replacement sprockets or phasers. Before initial start up I drained the engine oil and replaced the filter with Castro’* 5W30 and wix oil filter. Having the battery disconnected cleared all dtc’* for me . Then bled power steering and started the engine . I finished bleeding the PS and rechecked all fluid levels and road tested . Everything was functioning properly no MIL no CEL . Delivered to customer . Ran fine for approximately three months and that’* when he called me stating the engine was running rough and was noisy, check engine light was on. Brought it back into the shop, I tore it all back down and checked the timing was off it had jumped timing and the teeth on the phasers were worn. Should I have replaced the cam shaft phasers at the same time ? It’* giving me 4 fault codes P0016- P0019 but not P0007 or P0008 should I purchase and replace the sprockets and phasers can the wear down enough that they jump teeth?

The GM dealers will always replace them when doing the timing components.

Moved thread to Saturn.

Any explanation for enough slop to allow it to skip a tooth?

Which chain skipped?

Welcome aboard!