Truck experienced reduce power mode. Took to have codes ran and it showed 24 separate codes when engine light comes on. While riding down the road, truck will go into reduce power mode, shift automatically into 4x4, and several other notifications will appear. Taking to dealership and was told the electrical wiring harness was shorting out causing this issue. Cost around $700 for repair, happened one month later, took it back and no charge for the 2nd time. It is currently in reduced power now. Dealership stated to replace the wiring harness would cost over $3,000. Dealership stated this was a manufactures defect, but no recall was issued so all cost is on the owner.

- Linden, NC, USA

After completing a GM assisted engine rebuild the transmission oil pump is failing and transmission shifting era tic.

- Knightdale, NC, USA

Coolant control valve failure. Dealer inspected vehicle and it was confirmed that it needed to be replaced. Check engine light came on fan started spinning at a high speed and the vehicle went into low power mode. When I spoke with the dealer, this is a known issue so much to the point where the cooler control valve is on backorder and I-??ve had to wait for over a month now. Projected cost to replace with labor is over $3000.

- Rainier, OR, USA

The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that while driving at a moderate speed, the fuel warning light had appeared on the instrument panel. After fueling the vehicle at a gas station, the vehicle began to hesitate while depressing the accelerator pedal, with several warning lights, including the "Engine Power Reduced" and "Service ESC" illuminated. Due to the failure, the contact had the vehicle towed to a dealer. The dealer informed the contact that the starter needed to be replaced because the vehicle had failed to start. The mechanic performed a diagnostic test and discovered that the fuel injectors were defective and leaking fuel into the engine. The mechanic diagnosed the vehicle with engine failure and provided the contact with an estimate for repair. The manufacturer was notified of the failure but offered no assistance. The contact was then referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 68,000.

- Fort Pierce, FL, USA

Engine shut off while driving and was unable to restart.

- Delaware, OH, USA

While driving the active fuel management changed my truck from 4 cylinders to 8 cylinders. This is when I heard a loud bang and a bunch of lights came on the dash and my truck started shaking and shuttering. I was able to regain control of it, but I came close to crashing. I now require a whole new engine at 100000 miles. After talking to multiple shops this ks a known issue. While they dont always catastrophic fail, mine did and almost cost me to crash. This is a serious safety concern.

- Pulaski, NY, USA

The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that while driving at an undisclosed speed, there was a loud knocking sound coming from the engine compartment, and the vehicle shook violently, with several unknown warning lights illuminated. The vehicle was taken to the dealer, where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for further assistance. The failure mileage was approximately 84,000.

- Fort Wayne, IN, USA

My problem is the same as many others with the 3.0 Duramax engine. I h e the P0016 code indicating the the timing chain that can cost up to $10k and sudden engine failure if not repaired. My vehicle is only 5 years old and has 98K miles at the moment.

- Okmulgee, OK, USA

I was on a trip to Iowa and noticed a loud ticking noise starting in my engine. There was no warning lights on the dash to indicate any problems. I checked the oil and notice it was not registering on the dip stick. I added over a quart of oil and the noise continued. My truck was just at a dealer 2 weeks prior for an oil change and they noted that everything was good and in proper working order. No leaks or no other issues. I set up an appointment at a chevy dealer at the destination which I was traveling to for a check up. About 60 miles from the dealership, my check engine light went on. I immediately stopped and checked all my fluids which were showing normal ranges. I dropped my truck off for inspection and they advised me that my lifters need to be replaced. I authorized the repair and after the new ones where installed, they tested my truck and noticed that there was still a ticking noise coming from the engine and was not holding any oil pressure. They advised me that the motor needed to be replaced at a cost of almost $15,000. I will request all pictures and videos taken by the dealership for further inspection if needed.

- Rapid River, MI, USA

Had sudden engine failure at 82k and have been told I need a new engine. Can't afford it, GM says there's nothing they can do to help cover the repairs. I have a new engine on backorder, nobody knows when it will be in, they told me they have other customers who have been waiting for new engines for months.

- Thompsons Station, TN, USA

While driving in Southern Utah my truck gave me a Service ESC (Electronic Stability Control) Warning, Service Parking Brake Warning, and check engine light that was for code P0303. I had the vehicle towed to the local Chevrolet dealership and it was diagnosed with lifter failure and camshaft damage because of the lifter failure. Safety was compromised because of the failure of the ESC and the loss of power and stability of the engine. I didn't receive warnings prior to the failure. This appears to be a well-known issue with several service bulletins issued for the vehicle.

- Fort Worth, TX, USA

After three oil leak repairs in my LM2 3.0 diesel engine in my 2020 Chevrolet Silverado RST, you would think that would be enough to repair the manufacturer's defects, but it wasn't. I think the saying is fourth time is the charm? The third repair which was a second oil pan lasted a whopping 48 hours before leaking. This time it ended up being the timing chain cover that was leaking. Again, the service advisor mentioned that these are known to leak too due to a defect from the manufacturer. I even got a call from the service manager, and he said that anything area that could and does leak oil on these LM2 engines has been replaced and/or repaired, so I should be good for the future. I called into GM as per their instructions to update them on the fourth oil leak, and where the repairs were taking place. Fast forward to nearly two months later, and no one from GM attempted to contact me, and Jill stated that the case was closed and wouldn't disclose why. The only thing she could do was open another case. I declined since GM couldn't be bothered to address the issues they know they have in the LM2. The dealership the work was done in, the service advisors, the service techs, and the service manager all discussed in great detail the issues Chevrolet is having with the 3.0 diesel engine. GM knows this and refuses to address this. At this point, my vehicle spent 37 days in 2.5 months at the dealership fixing oil leaks that at any time could have caused engine failure and resulted in a crash. This truck is our dedicated family vehicle as my wife and I each daily Subaru WRX's. GM has done nothing and will do nothing. Someone needs to issue recalls to address the oil leak issues with the LM2 before it results in someone's death. I wish I wouldn't have wasted time contacting GM. I should have filed these complaints and got legal representation for the Magnuson-Moss Warranty Act. * loaner vehicle was given during the entire 37-day repair duration.**

- Woods Cross, UT, USA

The second oil leak repair and the first repair for the oil pan failed within one week of the previous repair. This is the third oil leak that occurred in the LM2 engine in the 2020 Silverado. It was identified as an additional leak in the oil pan which had already been repaired the week prior. This is a failure within seven days from the previous repair. I lost 1/2 quart of oil during a 650-mile drive back from vacation. I took pictures of the oil level before leaving and driving home. During our drive, we passed through an area called Yermo where it was 107 degrees at 11am. The two closest Chevrolet dealerships are either 45 minutes or 1.5 hours one-way. I was incredibly frustrated since imagine being stranded in 107-degree weather with your family on the side of the road unable to run AC. It is a serious life, health, and safety issue at this point. I called GM and opened a case expecting them to assist me with the issues with the truck. Fast forward to today, I spoke with Jill at GM, they closed the case without even reaching out to me. This was the third of four oil repairs that have been conducted on my vehicle and the LM2 engine. It isn't a safe engine to have. * loaner vehicle was given during the repair.**

- Woods Cross, UT, USA

This is for the second oil leak that occurred in the 2020 Chevrolet Silverado with the 3.0 diesel engine. It was identified as a leak in the oil pan. The previous repair was for the lower crankcase seal. The service advisor at the dealership stated this is another problem area with the Chevrolet 3.0 diesel engine, and a defect from the manufacturer. He also mentioned it is a common repair they complete on these LM2 engine. It is worth noting, the initial repair didn't last 60 days before another oil leak presented itself. This is the second of four repairs that were done on this vehicle. * loaner vehicle was given during the repair.**

- Woods Cross, Ut, UT, USA

There was a significant oil leak that was diagnosed during a routine oil change in March of 2025. The dealership that identified the leak attempted to pass it off as something that was out of warranty even though the vehicle had an additional six months and 45,000 miles of warranty (3.0 diesel). The leak was significant enough that loss of oil could cause the engine to fail and result in a crash. Subsequently, another dealership identified the leak and repaired the seal around the lower crankcase. It did not repair the oil leak- there are three additional reports/complaints to file.

- Woods Cross, UT, USA

Motor suddenly loss power and load knocking noise. After taking it to the dealer they said that number 3 cyl.connecting rod had an issue. This sounds like the same recall for the 2021 to 2024 6.2 engines. They gave me a quote for a new engine ( 20000) that was not available for 4 to 5 weeks if not more. I was on vacation at the time and ended up buying a new truck from them. I was not happy.

- Riverside, CA, USA

Having failure with the engine coolant control valve. Have taken my truck to the dealership for overheating and they always come and say that they can-??t find an issue. They also informed me that I need to bring it back when my motor blows a head gasket which is complete bull.

- Greensboro, MD, USA

Lifter failure on the 5.3L L84 engine. Due to Dynamic fuel management that come with the trucks.

- Austin, TX, USA

About 3 months after the 5 year 100000 mi warranty with only 70000 miles on the duramax diesel engine the exhaust brake part of the engine emissions/exhaust split along the weld. Have seen a number of these reported on the internet as well. Sounds like a manufacturing problem. The vehicle's check engine light came on and it's now at the dealership getting a new exhaust brake housing and bracket replaced. If this was in California or the 12 states listed would be covered for 8yrs/100000 miles.

- Barboursville, VA, USA

Engine seized my truck has been at the Chevorlet Tempe dealership I filed a claim with GM still no response.

- Phoenix , AZ, USA