2021 GMC Yukon engine problems

“As I was driving down the road at 60mph, no dash lights or warnings were present. All of a sudden, my 2021 yukon lost all power and I nearly crashed as I was in heavy, fast paced traffic. I got to the side of the road, and it was at this time the engine light came on. Car died and wouldnt start back up.”

“crank/rod failure on 6.2 engine. yes it is available same as other people with blown 6.2s yes, GMC dealer diagnosed crank failure no no. engine still runs but is knocking and squealing but dies after a few mins and won't restart till it cools off”

“VEHICLE: 2021 GMC Yukon, 5.3L V8 (L84). VIN: [XXX]. Mileage at failure: approximately 88,000. Component: Engine. INCIDENT DATE: XXX While I was driving on a highway, the engine began to misfire and I heard a ticking noise. The check engine light then began flashing, indicating a severe misfire. I pulled off the highway immediately to a rest area. The vehicle was towed to a GMC dealer. The dealer's diagnosis suspected failed valve lifters, and the repair orders call for a misfire diagnosis with the Bank 1 cylinder head removed, and replacement of the camshaft, lifters, and related parts. This failure caused sudden loss of engine performance at highway speed. The engine began smoking. My family and I were in the vehicle, and we were fortunate there was a safe place to stop. I believe this is a known defect. GM Service Bulletin PIP5776, "Misfire Due to Collapsed Lifter," covers 2021 GMC Yukons with the 5.3L L84 engine. It describes a misfire with a bent pushrod leading to a collapsed lifter or a lifter that comes apart, and it attributes the cause to an internal lifter concern. Many other owners of GM V8 trucks and SUVs have reported the same failure, and a class…”

“Bought 2021 GMC Yukon Denali new. Transmission failed at 70,000 miles. Engine has now failed at 111,000 miles. Both diagnosed at Capital GMC Atlanta, GA. Cost to replace transmission $8k (GMC paid half). Cost to replace engine $12k (GMC offered no assistance). Engine failure not related to current engine recall/investigation on GMC 6.2L V8 engines. This failure was on the top vs on the bottom (current recall).”

“In late February / early March 2026, at approximately 139,000 miles, my 2021 GMC Yukon Denali with the 6.2L V8 (L87) engine developed a loud knocking/rattling noise that sounded like a loose part inside the engine. The vehicle kept running, but the noise persisted. I took the vehicle to a GMC dealer. The dealer checked the VIN and told me there was no recall covering my vehicle. The engine was found to have internal damage consistent with connecting rod / bearing failure. A replacement engine was quoted at approximately $8,000. Because I could not afford that, an independent mechanic in Connecticut rebuilt the engine for approximately $5,500 in total (about $4,500 in parts plus $1,000 in labor), paid out of my own pocket. I have all the invoices for the repair. This failure appears to be the same connecting rod and crankshaft bearing defect covered by Recall 25V-274 for other 2021–2024 vehicles with the 6.2L L87 engine, but my VIN is excluded from that recall according to the dealer and the NHTSA/GM VIN lookups. No crash and no injuries occurred. I am reporting this failure so it is documented in NHTSA's investigation of L87 engines outside the recall…”

“The contact owns a 2021 GMC Yukon. The contact stated that while driving, the engine started making abnormal sounds. The vehicle was towed to a dealer. The manufacturer was notified of the issue. The dealer confirmed that the vehicle had experienced lifter failure and stated that further diagnostic tests were needed to determine if the engine needed to be replaced or if the lifters only needed to be replaced. The failure mileage was approximately 69,000.”