2015 GMC Yukon engine problems

Filed Sep 22, 2026 · Engine · WA

The vehicle developed a recurring cylinder #4 misfire with a flashing check-engine light, rough running, and reduced performance. Diagnostic code P0304 repeatedly returned. Replacing the #4 spark plug temporarily restored normal operation, but the misfire returned after a few hundred miles. The #4 plug was wet/oily, and fresh oil was found pooled in the #4 intake port while the other ports were dry. All eight spark plugs, ignition coils, and plug wires were replaced, along with the #4 fuel injector and both #4 valve-stem seals, but the misfire persisted. A valvetrain/lifter tick later became audible near 3,000 RPM. The failure has now been confirmed as a valvetrain failure that severely damaged/destroyed cylinder #4 and requires complete engine replacement. The vehicle is available for inspection upon request. This defect creates a serious risk of severe misfire, loss of engine performance, or complete engine failure while driving.

Filed May 23, 2026 · Engine, Fuel system · OR

While traveling at highway speeds on Interstate 5 in Oregon, my 2015 GMC Yukon Denali experienced a sudden, catastrophic engine failure with zero advance warning. The vehicle instantly lost almost all propulsion and power while surrounded by high-speed traffic, creating an immediate and severe safety hazard on a major interstate. The engine began making a loud, severe knocking noise, and I was forced to navigate across lanes without adequate power to reach the shoulder. The vehicle was towed and inspected by Point S in Creswell, OR, where diagnostics confirmed a P0300 random/multiple cylinder misfire, with cylinder 4 specifically misfiring. Using a stethoscope and scanner to isolate the failure, technicians confirmed a catastrophic rod knock failure at the bottom end of the engine. The vehicle was then taken to Sam’s Automotive Service, where a complete engine replacement was executed at a total out-of-pocket cost of $16,000. General Motors has a well-documented history of internal engine failures on these 6.2L V8 platforms, yet they have failed to issue a safety recall for vehicles experiencing this sudden, dangerous highway power loss.

Filed Feb 3, 2026 · Engine · WI

Noticed a tick sound. Sent to dealer. Lifter failed. Bent push rod. Took it in Nov 24th. Charged $7,100. Fixed all lifters and bent push rod. Was turning around in my driveway and vehicle just shut off. Took it back to same dealer in Jan 27th. Bad lifter. Same push rod. Still in shop. That’s two months and 2,000 miles and had same failure. That is absolutely ridiculous GM and I should be compensated for this. It has costed me $7100 dollars. They are fixing with a two year warranty but if the failures are so close together, who’s to say it won’t just keep happening. Not only is it a safety issue, it is hurting my finances. I drive this vehicle 2 miles to work at 25 mph, and religiously change the oil at 3,000 miles. It didn’t even get an oil change before it failed again. I am not happy and GM needs to be sued for this. I owe 20,000 on this truck and have spent 7,000 already, and it keeps failing. There needs to be a recall for this model year, and it needs to be a permanent fix. GM knows the quality of this motor is horrible and they won’t do anything about it. It’s not safe. They can my truck for $20,000

Filed Nov 7, 2025 · Engine · TX

While driving my 2015 GMC Yukon Denali on the highway, the vehicle suddenly began shaking and lost power. I immediately exited the highway for safety and had to “nurse” the vehicle about two miles at 10–15 mph to reach home. The vehicle would no longer run afterward. A mechanic later diagnosed a lifter and camshaft failure. This is a known and common issue with GM 5.3L and 6.2L engines that poses a serious safety risk when it occurs at highway speeds. No warning lights or prior symptoms were present before the failure. I did not report it to the dealer, but the vehicle had to be towed to a mechanic for diagnosis. The vehicle is available for inspection.

Filed Nov 6, 2025 · Engine · KY

6.2L engine, collapsed hydraulic lifter AFM failure, required $7400 in total repairs. All lifters, camshaft, high pressure fuel lines, high pressure fuel pump, intake manifold & miscellaneous parts and gaskets replaced by selling Dealer at 94000 miles. No help of any kind from GM or Dealer. This is a WELL KNOWN FAILURE FOR THESE ENGINES!

Filed Jul 16, 2025 · Engine, Transmission · TX

Driving down the expressway at 65MPH, and the Vehicle completely stops, almost causing a collision. After researching the problem at the GMC Dealer, it appears that the entire engine has internally failed. Apparently it was a Complete Engine Failure.

Filed May 16, 2025 · Engine · 100,000 miles · FL

The contact owns a 2015 GMC Yukon. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to pull to the shoulder of the roadway, where the vehicle failed to restart. No warning lights were illuminated. The vehicle was towed to an independent mechanic, who diagnosed a failure with compression in cylinder 7, resulting in damages to the engine. The contact was informed that the engine needed to be replaced. The vehicle was repaired. After investigating the failure, the contact related the failure to the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling), but the VIN was not included. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the federal safety agency Hotline for assistance. The failure mileage was 100,000.

Filed May 5, 2025 · Engine · MS

Started my 2015 Yukon XL, drove approximately 6 miles to get gas and was to head out onto the highway. After gassing up and starting engine it began to idle very rough with a shake going on and ticking noise. No previous signs of any issues. Slowly drove back to my house at 20 miles an hour and called Mandal GMC dealership. They suggested having it towed to them for inspection. Upon inspection they said the AFM/DOD #1 exhaust lifter was bad and needed replaced. They replaced all of Bank one lifters and said their was no damage to camshaft. Drove it that night after repairing it and everything seemed fine. They called the next morning and said when they started it up the ticking was back again. They then supposedly took off head cover and inspected the camshaft again and said it was damaged and I would need a new engine to the tune of $18,000.00. I purchase it in 2021 from them use and paid $33,000.00 and now still owe even more than the engine repair. I said it would cost more than the vehicle was worth and they had done $4,000.00 of repair that didn’t even get the issue fixed. I am a senior on Social Security and can not afford to continue to pay 20,000.00 for the loan and then another $18,000.00 for a faulty engine design that caused the problem in the first place. May have to join the thousands of others in the class action to get GM to not put out such untrustworthy engineering. Now $37,000.00 piece of Yard Sculpture !! The morning that it occurred was the first sign of flashing engine warning on dash.

Filed May 2, 2025 · Engine · AR

The Yukon was driving normally and just lost power while driving 55mph on the highway. Then I got off the highway to pull over and check it out and the Yukon started shaking while running and in Park. The truck would not drive over 30mph without shaking and what sounds like misfiring.

Filed Mar 20, 2025 · Engine · LA

With my child in the car, on a highway with no shoulder, I experienced lifter failure. It caused the vehicle shake and lose power with cars driving behind me at 55-60 MPH with nowhere to pull over. The engine just stopped as I was finally able to make it to a driveway safely. Problem was identified by dealership and my engine had to be rebuilt. I purchased the car second hand 3 months prior with no warning or symptoms. The car was inspected at the dealership by the extended warranty company rep. The extended warranty only cover a portion of the cost. The collapsed lifter cause damage to the camshaft and bent rods. The car only had 107,000 miles. If I were not able to pull off before the engine stopped, my daughter and I could’ve easily got rear ended on a Major state highway. The car was difficult to control due to the engine shaking the entire SUV.