2025 Chevrolet Suburban 1500

Purchased the vehicle on April 7, 2025. On 7/15/25, the car had 6948 mi. and started running rough, had a loss of power, an odor from the engine, and then on the display: check engine, blinking green vehicle light, and a message stating that the car was lowering for stability control. Took the vehicle to the closest Chevrolet service. The service dept. determined that code found P0307 and P0300, cylinder seven had the most misfires above 500. After completing oil service, the vehicle began to click on the passenger side; however, it was not misfiring. They inspected and found potential lifter issue. Found ticking coming from cylinder 7 and verified misfires. Found 2 pushrods damaged. Heard noise coming from cylinder 4, removed valve cover, removed rocker arms, and found 1 pushrod damaged. They removed and replaced all lifters and 3 pushrods. They stated there was no more noise //after this repair. These repairs were completed on July 25, 2025. On 8/15/25 took back to service because it continued to run rough and made excessive noise and whistling when starting the vehicle. The dealer inspected and heard the noise, inspected the vehicle exhaust leak, checked exhaust manifolds, pipe connections, and determined there were no issues found. On 9/26/25 at 11,821 miles the car was making excessive noise, running rough, and was losing power. Drove home, and the vehicle was running rougher and losing power. No check engine lights or warnings were present. Drove home, and the vehicle was running rougher and losing power until it turned off. Towed in. Maintenance techs determined catastrophic engine failure, all bearings and engine rods seized. After this repair hen the catalytic converter failed. This car has been out of service due to engine failures for 43 days out of the 204 of ownership.

Cause unknown, however, I have discovered that the engine in my Suburban, the Engine code LZO 3.0L Duramax, has damaged itself internally. I have been told that there is a large batch of engines that have this same problem, and the dealership I sent my car to has several cars in the same position. This problem is causing the engine to lock up or completely quit. This could be serious depending on when this failure happens. Currently, they are telling me that I am months away from getting a new engine due to a back order. Vehicle still in shop, so I do not have records yet, but I will be happy to give them once I have them.

My Onstar system is not working properly. I first noticed the Forward Collision light then the Wifi hotspot features not working. Reached out to onstar they couldn’t help then referred to dealership. Visited dealership 8/12/2025 was told there’s no error code although they see what’s happening. Doing further investigation of my own i found out this is a very well known issue amongst General Motors, Onstar and the dealerships selling these vehicles. There are varying issues customers are having from wifi not working to vehicles completely shutting down in traffic. Once my visit to the dealership commenced i was informed the Telematic Control Module” is on back order with no estimate on deliveries as there’s “others waiting also” this is a scary situation. I am worried that my issue is going to progress into a bigger problem. I drive 23 miles to work and 23 back. I am scared that my module will eventually fail when i am on the highway…..this is terrifying! Over 80k to play roulette.

The contact owns a 2025 Chevrolet Suburban. The contact stated that the "Adaptive Cruise Control Temporarily Unavailable" message was displayed on the instrument panel. The vehicle was taken to a local dealer where the vehicle was diagnosed, and the contact was advised that the radar was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 23,686.

The engine in 2025 Suburban (6.2L V8) has failed and the car is not drivable. It is currently in a Chevy dealership service department waiting for parts. The 2025 model is not listed under the recall. However it should be, I know of 3 2025 engines that have recently failed. I was passing a vehicle and as I took my foot off the accelerator the transmission shifted 2 times and then the engine shut off and the car was coasting. We had no indication that the engine shut off, just several messages on the screen. ( Press start button, and conditions not correct for shifting.)