GM 3.6L HFV6 Timing Chain Stretch (2007–2017)

GM’s 3.6L HFV6 engines (LY7, LLT, LFX, LF1, LWR) are known for timing chain stretch, leading to cam/crank correlation codes (P0008, P0009, P0016, P0017) and expensive repairs. Low oil change intervals and oiling system sensitivity accelerate wear.

Ref ID Year(s) Make Model Should Purchase? Reason Notes
2007 2008 2009 Chevrolet Equinox, Malibu Not Suggested Timing chain stretch; cam/crank correlation faults Engine: 3.6L HFV6
RPO: LY7
Early design with high chain wear rate
2007 2008 2009 GMC Acadia Not Suggested Chain stretch leads to drivability issues Engine: 3.6L HFV6
RPO: LY7
Sensitive to oil change intervals
2007 2008 2009 Buick Enclave Not Suggested Frequent P0008/P0009 codes Engine: 3.6L HFV6
RPO: LY7
Often requires full timing set replacement
2010 2011 2012 2013 2014 2015 Chevrolet Traverse, Camaro Not Suggested DI version still prone to chain stretch Engine: 3.6L HFV6 DI
RPO: LLT
High soot → oil contamination → chain wear
2010 2011 2012 2013 2014 2015 GMC Acadia Not Suggested Chain stretch causes cam/crank sync errors Engine: 3.6L HFV6 DI
RPO: LLT
Expensive repair ($2,000–$3,500)
2010 2011 2012 2013 2014 2015 Buick Enclave Not Suggested Same LLT timing chain defect Engine: 3.6L HFV6 DI
RPO: LLT
Requires full timing set replacement
2012 2013 2014 2015 2016 2017 Chevrolet Impala, Equinox Not Suggested Improved but still chain stretch prone Engine: 3.6L HFV6
RPO: LFX
Better than LLT but still problematic
2012 2013 2014 2015 2016 2017 GMC Terrain Not Suggested Chain stretch + oiling sensitivity Engine: 3.6L HFV6
RPO: LFX
Still produces P0008/P0009 codes
2010 2011 2012 Chevrolet Traverse Not Suggested Chain stretch common on early DI engines Engine: 3.6L HFV6
RPO: LF1
Same timing chain defect as LLT
2010 2011 2012 GMC Acadia Not Suggested Chain stretch → cam/crank sync errors Engine: 3.6L HFV6
RPO: LWR
Requires full timing set replacement

Summary

GM’s 3.6L HFV6 engines (LY7, LLT, LFX, LF1, LWR) from 2007–2017 are widely known for timing chain stretch, cam/crank correlation codes, and expensive repairs. These engines are highly sensitive to oil change intervals, and many require full timing set replacement well before 150k miles.