2020 GMC SIERRA 1500 Complaints

On [XXX] at around noon I was driving my 2020 GMC Sierra northbound on [XXX] 26 miles north of Moab Utah. My truck died and I attempted to coast to the next passing lane but did not make it. The shoulder was about 3 feet wide and then had a steep drop off. I pulled over as far as I could but the majority of my truck and trailer was still in the only northbound lane. The northbound traffic was forced to cross over the double yellow into the oncoming southbound traffic. The concern was getting rear-ended by northbound traffic behind me or a head-on collision with the northbound traffic veering into southbound traffic. I made several attempts to restart the truck and the dash just goes blank with no attempt from the starter. We waited for a tow-truck and about an hour into this wait Utah Highway Patrol arrived and parked behind us with his lights on warning traffic from both directions. There were no precursors to this failure or notifications. I didn’t even hear any noises. There was no physical damage or any leaking fluids. It just quietly stopped. John Elway Chevrolet informed me the bearings failed and the engine seized. I wanted to keep the core for evidence due to learning about the numerous catastrophic failures of the L87 engine I had. Keeping the seized core was going to cost me double the cost of a rebuilt one ($7000). When I asked the service Manager, Ben why its twice the cost? He said, “GM doesn't want you keeping the core and they can set whatever price they want .” I have had this truck since it was new (6 miles) and noticed unusual oil consumption early on. I would never make it to the next oil change without having to add oil, even with the very first oil change. I inquired about this with the dealer and told this extreme oil consumption was normal and given Bulletin 01-06-01-011M. I did not involve my insurance because they do not cover engine failure. I paid $12,653.97 for a remanufactured long block. Of that was $2469.93 was for parts not need INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INF

Check engine and ECM errors. The dealer replaced one bank lifter. Shortly after, a similar issue was caused by reassembly. Approximate mileage: 30 K. A month later, the same issue, but this time the vehicle was not drivable, with very low engine power. The dealer stated lifter failure and camshaft damage, engine replaced January 2024, mileage 31 K. Currently 42K and had one instance of ECM error, which only lasted a few seconds, but the engine faltered and lost power. At the most recent oil change, the dealer said no error codes were present. GM indicated that my VIN is not covered under the most current recall. Since the engine was replaced in 2024, there is virtually no possibility that the engine replacement was not a new engine and should fall under this most current recall.

I was driving on the frontage road that enters the freeway when then engine suddenly failed and stalled. It lost power and seemed like it was misfiring. All the warning lights on the dashboard came on as this happened but there were no warnings lights, messages, or symptoms before this happened. The sudden loss of power posed a risk to my safety because it could have caused a crash or left me stranded. I had my vehicle towed to the Freeway Chevrolet dealer in Chandler, AZ where they inspected the vehicle and confirmed the engine had a camshaft and lifter failure.

I have taken my vehicle to 3 seperate mechanics (GMC, AAMCO and Independent). They all agree that my valve body inside the transmission must be replaced. The problem is that valve bodies are on a national back order and cannot be fullfilled for months, putting my transmission at risk for further failure. Reading online forums, there are many GMC owners facing this same issue. The mechanics at GMC are requesting that I change out my entire transmission, since that will be a quicker solution than waiting months for that valve body. Now, I am being told that they are having difficulty locating an original manufactured transmission. This puts me in a serious bind because my truck is my only vehicle and there are no valve bodies or transmissions to fix this issue. My truck is only a 2020 and I just surpassed 100k miles. There were no dashboard warning lights that indicated my trucks problem. Only the fact that my truck is shuddering when shifting gears and that a diagnostic tool had to find the source of the problem. This problem started about 5 months ago and has progressivly gotten worse.

The contact owns a 2020 GMC Sierra 1500. The contact stated that occasionally while driving at various speeds, several unknown warning lights remained illuminated, and the vehicle lost motive power. The vehicle was taken to a local dealer to be diagnosed, and the contact was informed that DTC: P0016 was retrieved, and it was confirmed that the engine had failed and needed to be replaced. The vehicle was not repaired. The contact referenced NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The contact expressed a concern that the remedy was the same engine that was prone to failure. The manufacturer was notified of the failure. The approximate failure mileage was 150,000.

1) Complete Engine Failure. Vehicle is no longer is in possession for inspection but pictures and video can be provided. 2) My Truck stalled at 70 MPH going down the interstate. I was lucky to be driving in the right lane to glide to a complete stop. This could have been way worse, not just for myself but for others. 3) Shortly after the loss of propulsion on the interstate. The engine started knocking very loud and I brought it into Boucher GMC of Brookfield. After about a week, the conclusion was I needed a new Engine. The Bearings, camshaft, rods and other components within the engine were damaged. The dealership said it was because of Bad Oil. 4) Parts were inspected and Dealership provided pictures. Not sure what they did with the junk parts. 5) I initially brought in the vehicle where it was purchased at Kunes of Stoughton WI for a Check engine light that read a P06DD error code at 56472 miles on the truck. They performed a software update and sent me on way. Since then, I was dealing with a on and off engine light which eventually brought me to a engine replacement at about 70,000 miles. None of this was covered under warranty and I had to pay for all of this out of pocket. In the events of all this. GMC had my truck for about 3 months. I had to purchase another vehicle because it was cheaper then renting one, GMC didn't have a loaner I could use. I could not perform my everyday work tasks besides getting to and from work, because I did not have a truck to carry my everyday work tools. Now understanding the full impact of this faulty engine and that I could have done harm to others or my self, has me worried about driving a GM vehicle. After I received the new engine, approximately 2000 miles later, The new engine, not rebuilt started making a knocking noise, only to find out, it was the same issue after bringing it to the dealership. No engine lights or nothing. People should be scared to drive a vehicle with the L87 engine from GM.

3.0 LM2 Duramax engine failed at 91,000 miles. It needs a new engine and they are available with a 2-3 week wait time. The engine failure has been inspected and confirmed by the dealer. No symptoms or check engine lights were on prior to the failure. Problem first appeared 03/2025.

I have had two engine failures within 2 years of buying a new GMC truck. The first occurred at 24,181 miles whereas i found engine failures is an all to common occurrence with these 5.3 liter engines, failures are wide spread, tons of complaints can be found with a simple internet or youtube search. The second engine failure occurred at 45,517 miles, again with lifer falling apart. Several service bulletins have been issues including reworking vehicles on dealers lots to replace faulty components but in my case i had over 16000 miles so they put the same parts in again and did not touch the other side which then failed two years later at in my case both were attributed collapsed lifter. This is a safety concern, there is no indication this is about to occur. The vehicle loses power, shakes, instrument panel lights up with various different warning lights. If you are passing another vehicle and this occurs it can be frightening as you have no idea what is happening and why you are no longer accelerating if you are passing some vehicles. The value of these vehicles is now also diminished, who wants a GM vehicle with two engine failures with 45k miles? No one, because it more than likely going to keep occurring until the engine is damaged beyond repair.

The contact owns a 2020 GMC Sierra 1500. The contact stated that while attempting to start the vehicle, the vehicle failed to start. There was no warning light illuminated. The contact pushed the vehicle out of the garage. The vehicle was towed to a dealer where it was diagnosed that the spun bearing had failed. The contact was advised that the engine needed to be replaced. The engine was replaced. The contact stated that recently there was an abnormal sound coming from the engine. The vehicle was not diagnosed or repaired after the most recent failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 40,000.

The transmission is jerking and sometimes it will not shift enough to get out of others ways. Severe slippage in the transmission I have taken the truck to the shop 3 times for the same issue. Now they tell me I need a new transmission.