NHTSA Complaint #11637042 — 2015 GMC YUKON XL

My wife drives a 2015 GMC Denali with the 6.2L engine. My daughter has an almost identical 2016 Denali with the same 6.2L engine. The 2015 had a serious event at approximately 125,000 miles when one of the rocker arm springs broke under ordinary driving conditions and caused the vehicle to be disabled in the midst of heavy traffic. The 2016 had a virtually identical event at 135,000 miles, which caused the rod to be ingested into the cylinder. I believe the rocker arm springs on these engines are defective, also evidenced by after-market double springs being sold for this engine. I have replaced all rocker arm springs on the 2016 with double springs and will do so shortly on the 2015. The GM dealer in Corpus Christi, TX where we had the 2016 towed told me that the only solution for it was to replace the entire engine at a cost of $11,000+. I paid the dealer $1,000+, towed the truck to San Antonio, and had a mechanic in my employ rebuild it for approximately $2,000. The 2015 had not broken the rod and was repaired by a dealer in San Antonio for approximately $1,250. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)