2018 Gmc Sierra 1500 Engine Problems

Your truck's 6.2L engine is consuming oil at an unusually high rate, and you've found heavy metal particles in the oil, which suggests internal engine wear or damage. You're hearing a loud ticking noise from the engine. At 120,789 miles, this indicates a serious internal engine problem that likely requires engine repair or replacement.

Your engine's fuel injector has failed, causing repeated misfires that make your truck lose power unexpectedly while driving—the engine hesitates, shakes, and struggles to accelerate, especially on highways or when merging into traffic. This sudden power loss is a serious safety hazard because you can't reliably maintain speed or respond quickly when you need to, putting you and other drivers at risk during lane changes and passing maneuvers. The dealership has confirmed the injector is faulty, and your truck has been out of service for three months. You'll likely need fuel injector replacement to restore normal engine operation.

Your truck shook violently when starting and lost power, though restarting it made the problem go away temporarily. A mechanic found metal debris inside the engine and detected a misfire in cylinder #2, which typically requires engine replacement. However, the issue stopped after the mechanic tightened loose wires connected to the engine control module (ECM). Fixing this may involve cleaning metal particles from the engine, replacing ignition components, and ensuring all electrical connections are secure.

Your engine's lifters collapsed while you were driving, which bent a push rod and damaged the camshaft, causing a significant loss of power and requiring thousands of dollars in repairs. According to your mechanic, the active fuel management system caused the lifter failure, and there was no warning before it happened. The fix will require replacing the collapsed lifters, bent push rod, damaged camshaft, and potentially addressing the active fuel management system.

Your 2018 GMC Sierra 1500 experienced hesitation and delayed acceleration when starting from a stoplight, with RPMs climbing before the vehicle finally accelerated. The dealer found that a connecting rod inside the engine had failed and metal shavings were circulating inside the engine. Your engine will need to be replaced to fix this problem.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving on a neighborhood road at 40 MPH, the check engine warning light was flashing with an abnormal knocking sound coming from the engine, and the vehicle was vibrating abnormally. The contact pulled over and used a diagnostic scanner to perform a diagnostic test on the vehicle. The scanner retrieved DTC: P0301 (Cylinder #1 Misfire). The vehicle was towed to a local dealer to be diagnosed, and the contact was informed that the lifters, pushrods, camshaft, sparkplugs, and oil pump were faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 111,000.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at various speeds, there was an abnormal banging sound coming from the vehicle. There was no warning light illuminated. The contact inspected fluids but found no defects with the vehicle. The vehicle was then taken to an independent mechanic, where the mechanic discovered that the lifters and cam shaft were defective. Due to the failure, the engine was replaced. The contact stated that recently, the abnormal tapping sound returned. The vehicle was taken back to the independent mechanic, who confirmed that the failure with the lifters had returned. The vehicle was taken to a dealer who confirmed the lifter failure, and the contact was provided an estimate for the repair. The manufacturer was notified of the failure, and the contact was provided a case number. The contact was then referred to the NHTSA to report the failure. The vehicle was not yet repaired. The failure mileage was approximately 90,000.

Radiator cracked along outer edges. Similar to previous TSB’s as released by GM, but my vehicle doesn’t fall under the years covered by that TSB

The contact owns a 2018 GMC Sierra 1500. The contact stated while his mother was driving 75 MPH on the highway, there was a popping and ticking sound coming from the engine, and while depressing the accelerator pedal the vehicle failed to respond. The driver was able to pull over to the right side of the road and waited for tow truck assistance. A dealer was not contacted. The vehicle was towed the dealer and was diagnosed and determined that the engine needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure, and informed the contact engine would take a while to be ordered. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was 58,000.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and depressing the accelerator pedal, the vehicle failed to accelerate as intended. The message "Reduced Power" was displayed, and the RPMs increased. Additionally, the vehicle jerked, and the contact noticed that there was smoke coming out of the exhaust pipe. The vehicle was driven to the contact's residence. The vehicle was taken to an independent mechanic, where it was diagnosed that the starter, the battery, the fuel pump, the oil pump, the oil pump sensors, and the fuel injectors had failed and needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The contact stated that while driving at an undisclosed speed, the vehicle stalled. There was no warning light illuminated. The vehicle was able to restart; however, the failure recurred. The vehicle was driven to the contact's residence. The vehicle was not repaired. The manufacturer was made aware of the failure, but no assistance was provided. The failure mileage was approximately 133,742.

My vehicle was a well maintained 2018 GMC Sierra 1500. It has 58000 miles. I was driving in 30 mph zone thank God. Heard a loud boom and the truck lost power and shut off. I got out and oil was pouring out. I took it to the GMC dealership and they told me the engine failed. They didn’t know why or what caused the failure. But said they is a hole in the block and all they can say is something in the engine failed.

Lifter when bad during engine start up. (known issue)

Spun main bearing in motor. Motor blown. It is available for inspection. GM mechanic inspected and quoted for new motor. Vehicle shut down going down interstate at 78 mph. No warning.

The contact owns a 2018 GMC Sierra 1500. The contact stated that at start-up there was an abnormal ticking sound coming from the engine. There were no warning lights illuminated. The local dealer was contacted; however, the vehicle was not diagnosed. The contact was informed that the vehicle was out of warranty, and that the VIN was not under recall. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 17,000.

Lifters failed and damaged engine at 68000 miles

DRIVING 70 MPH ON [XXX] IN MODERATE TRAFFIC WHEN MY VEHICLE SUDDENLY SLOWED DRAMATICALLY AND BEGAN TO SHUDDER . I WAS IN THE MIDDLE LANE OF THREE WESTBOUND MARKED LANES AND WAS ALMOST HIT BY A DRIVER BEHIND ME WHICH HAD BEEN FOLLOWING TOO CLOSELY. THE CHECK ENGINE AND TRACTION CONTROL LIGHT CAME ON AND MY OIL GAUGE WENT TO THE HIGH SIDE. I EXITED ONTO [XXX] AND AT 40 MPH THE TRUCK WOULD SHAKE AND SHUDDER UNTIL I DROVE THE 6 MILES TO MY RESIDENCE. ON [XXX], I HAD THE VEHICLE TOWED TO LASH GMC DEALERSHIP IN JOHNSTOWN OHIO. ONCE THERE THE VEHICLE WAS DIAGNOSED WITH A FAILED LIFTER THAT BROKE INTO PIECES RESULTING IN A BENT ROD AND DAMAGED CAM SHAFT. THE DEALER RECOMMENDED FULL ENGINE REPLACEMENT DUE THE SEVERITY OF THE FAILURE. THE TRUCK IS A 2018 GMC SIERRA DENALI WITH ONLY 65,449 MILES ON IT. IT COST ALMOST $70,000.00 NEW AND THE REPLACEMENT ENGINE COST ME $14,221.96. I FEEL MY PERSONAL SAFETY WAS JEOPARDIZED IN THIS INCIDENT. SINCE THAT TIME I HAVE RESEARCHED THE 6.2 GMC ENGINE ONLINE AND HAVE FOUND REPORTS OF NUMEROUS SIMILIAR FAILURES AND INCIDENTS INVOLVING THE ENGINE IN QUESTION. I TRULY FEEL NHTSA SHOULD TAKE A STRONG LOOK AT THE ENGINE FAILURES INVOLVING THIS ENGINE AND FORCE GMC TO REPAIR OR REPLACE THE ENGINES IN QUESTION DUE TO THE SAFETY ISSUES INVOLVING THE ENGINES FAILURES IN TRAFFIC AND THE RISK ASSOCIATED WITH AN OCCURENCE. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I have a 2018 GMC Sierra 1500 with a 6.2 motor. Back in December of 2024, I had to replace a tie rod, cam shaft, and the lifters. $8400 to get everything replaced. Since my warranty had expired, I had to pay all of this out of pocket. I know there is currently an investigation going on in GMC's 6.2 motors. Almost 900,000 engine failures. This is unacceptable. GMC just needs to man up and send out the recall notice. Since I have already had to pay for my replacements, GMC should do the right thing and and cut me a check.

Lifters and cams fatal failure, requiring extremely pricy replacement of the parts affected or replacement of the entire engine!

My 2018 Silverado 1500 has had 3 cylinder 4 misfires over a 9 month period that had to be repaired after warranty. This caused the repair/replacement of the lifters. I have had this happen for a forth time this year January 7 2025 with the same code of "cylinder 4 misfire". That means four of the same issues in one year. I can be driving along smoothly, then suddenly from one light to the next, the check engine light comes on with the misfire to cylinder 4 coming on. It was shared with me the AFM can cause this to happen. On the third time of misfire, I saw a little smoke, then once it was repaired with lifters replaced, no smoke and back to running smoothly. This time the intake cam lobe was scored which voided the warranty. I am now at a crossroad as to what to do now, and have parked the truck for now. It is my understanding the 5.3L engine was considered a solid engine until the AFM was installed. Did I mention this is the first "truck" I have ever owned? I have had a Chevrolet vehicle since I was able to drive, and have never had engine problems of this magnitude. My concern now is that this could cause my engine to lock up while I'm driving around and cause a possible accident. I depend on this truck as my mode of transportation, but now I have to make a decision that impacts me greatly as a senior citizen on a fixed income.

The failure was a lifter collapsed in my vehicle's motor. I had reduced power and major shuttering due to the issue. If I had been towing a load I would have possibly become a hazard by not maintaining a speed that would have been able to keep up with traffic flow. Also if I had been in an congested traffic area I would have been slower to clear or have major breakdown causing increased backups. It was confirmed by a local shop. There were no warning lights at the time of incident, nor leading up to this incident. Fortunately no accidents or disruptions happened and I had to be towed in to a repair shop.

Engine failed before 100,000 miles. Lifter failed leading to a damaged camshaft and replacement of lifters being require. Required 10,000$ in repairs. Failure light appeared suddenly. No issues were known of ahead of incident.

This vehicle has 88400 miles, it out of warranty, which I know this, I use AMSOIL ASM SIG SERIES SYN SAE 0W-20 , 5.3L GAS. TWO YEARS AGO, I CHANGED OIL AT RICHARD BUICK GMC IN DAYTON, OH AND SENT A SAMPLE OF THE OIL TO OIL ANALYZERS FOR AN ANALYSIS, THEY SET IT BACK, IT SHOWED THERE WAS A LEVEL 4 SEVERE GASOLINE IN THE OIL. THEY CHANGED THE HIGH SPEEP FULE PUMP, BOTH IN JECTORS, AND IT THOUGHT IT WAS FIXED, ON 12 - 11 -24 HAD THE OIL CHANGED AT LOCAL BOYS SERVICE CENTER, SENT A SAMPLE OF THE OIL-TO-OIL ANALYZERS AND RECIEVED BACK, A SEVERE FUEL LEAK OF GASOLINE IN THE OIL, i DON'T THINK THAT MANY DRIVERS WHO HAVE THIS VEHICLE KNOW ABOUT THIS DANGEROUS PROBLEM, IT COULD CAUSE AN ENGINE FAILURE OR EVEN WORSE, GENERAL MOTORS NEEDS TO FIX THIS PERBLEM.

Vehicle is a 2018 GMC Sierra Crewcab 4x4 with a 5.3 engine. The vehicle was purchased new in Washington and serviced at the Chevrolet dealership in Oregon within vehicle recommended service intervals. At 64K miles, the engine developed a sudden AFM lifter issue. Lifter for cylinder #6 came apart causing the engine to miss, smoke, have excessive oil on the spark plug, and low cylinder PSI (75 compared to others at 200+). Vehicle is just outside of it's 5 yr/60K powertrain warranty. Vehicle is undrivable and will need probable engine replacement due to damage from AFM lifter failure. My mechanic verified the miss, oil on the spark plug, and low PSI. The local Chevy dealership removed the valve cover, inspected, and advised that the lifter came apart. Dealership wants $1200 to pull the head to determine extent of damage and $4-5K to repair valves or $12-14K for engine replacement. GM offers no assistance at this point.

The contact owns a 2018 GMC Sierra 1500. The contact stated that after starting the vehicle, there was an abnormal ticking sound coming from engine compartment. The vehicle was taken to the local dealer who diagnosed that the exhaust manifold bolts had fractured and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not yet notified of the failure. The failure mileage was 64,000.

I am told by a GMC dealer that my engine mount is cracked/worn and needs replacing otherwise the engine can fall out. My mechanic tells me this is a common problem with GMC trucks; specifically the driver’s side engine mount. Perhaps a recall is necessary if this is a common issue. My vehicle is a 2018, so only 5 years old.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while turning left at an undisclosed speed, the vehicle lost motive power. No warning light was illuminated. The contact was able to restart the vehicle; however, the failure recurred. The vehicle was taken to the dealer; however, the dealer was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 72,000.

When I’m towing my small boat, my temperature gauge starts to rise on my engine and there are no warning lights and it has caused me to have to pull over. I have told the dealership about this. Everyone seem to act like it’s no big deal but when I’m having to pull over, because I’m afraid my motors getting too hot, it’s a problem. And not only that even when I’m not towing anything my temperature gauge keeps going up then back down up and then back down never in my life have I experienced a vehicle doing this

Radiator failed. Mileage is under 60k. It is currently being replaced by dealership. Dealer Representative noted that it is a fairly regular occurrence for these models. So much so that the dealership stocks this replacement radiator(hard for me to understand). There was no indicator lights to alert to this malfunction, it was noticed after work one afternoon when coolant was dripping out of the front of the vehicle.

47,012 MILES RADIATOR FAILURE, LEAKING BADLY. GM DENIED REPAIR UNDER WARRANTY

TL* THE CONTACT OWNS A 2018 GMC SIERRA 1500. THE CONTACT STATED THAT THE VEHICLE VIBRATED ABNORMALLY WHILE DRIVING. THE VEHICLE WAS TAKEN TO INGERSOLL AUTO OF DANBURY (84 FEDERAL RD, DANBURY, CT 06810, (203)885-7774) FOR AN OIL CHANGE AND THE ENGINE WAS FLUSHED ON FOUR OCCASIONS. THE CONTACT STATED THAT THE VIBRATION INCREASED. THE VEHICLE WAS TAKEN TO THE SAME DEALER AND A TIRE ROTATION AND ALIGNMENT WAS PERFORMED. THE CONTACT WAS ALSO INFORMED THAT THE TIRES NEEDED TO BE REPLACED. THE TORQUE CONVERTER WAS ALSO REPLACED HOWEVER, THE FAILURE REMAINED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND REFERRED THE CONTACT TO NHTSA FOR ASSISTANCE. THE APPROXIMATE FAILURE MILEAGE WAS 47,000.

AT 55000 MILES THE RADIATOR STARTED TOO LEAK GM WOULD ONLY PAY 250.00 DOLLARS OF THE 876.00 IT COST

WHILE DRIVING WITH THE ROADS IN A WET CONDITION, FOR VARIOUS LENGTHS OF TIME, AND IN DIFFERENT MANEUVERS, THE SERVICE ENGINE LIGHT WILL START FLASHING AND THE VEHICLE WILL BEGIN TO LOSE POWER. AFTER A FEW MINUTES, THE SERVICE ENGINE LIGHT WILL GO SOLID AND THE TRACTION CONTROL LIGHT WILL ILLUMINATE. THE VEHICLE LOSES MORE POWER. ON BRAKING, JUST BEFORE THE VEHICLE COMES TO A COMPLETE STOP, THERE IS A CLUNK IN THE TRANSMISSION AND THE VEHICLE LURCHES. THIS HAS OCCURRED 6 TIMES IN THE LAST 14 MONTHS. UPON INVESTIGATION, TROUBLE CODE P0308 SHOWS IN THE OBD TOOL. THE ISSUE COULD NOT BE REPRODUCE BY THE DEALERSHIP SO THERE HAS NOT BEEN ANY RESOLUTION, JUST THOUGHTS.

TL* THE CONTACT OWNS A 2018 GMC SIERRA 1500. THE CONTACT STATED THAT A COOLANT SMELL WOULD EMIT FROM THE VEHICLE UPON EXIT. THE CONTACT ALSO STATED THAT HIS VEHICLE HAD BEGAN TO LOSE COOLANT AT AN ABNORMAL RATE AND HAD TO BE FREQUENTLY REPLACED. THE CONTACT TOOK THE VEHICLE TO MCCONNELL AUTOMOTIVE (3150 DAUPHIN ST, MOBILE, AL 36606) WHERE THEY CONFIRMED THAT THERE WAS A CRACK IN THE RADIATOR WHICH RESULTED IN A COOLANT LEAK. HE WAS ALSO INFORMED THAT THERE WAS NO RECALL ON THE VIN AND THAT THE WARRANTY DID NOT COVER THE REPAIR. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE AND PROVIDED THE SAME INFORMATION AS THE DEALER. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS APPROXIMATELY 42,000.

THE RADIATOR IS LEAKING COOLANT WITHOUT ANY REAL CAUSE AND I WAS TOLD THE ENTIRE RADIATOR NEEDS TO BE REPLACED.

I HAVE HAD MY GMC SIERRA 1500 FOR ALMOST 3 YEARS. I HAVE A LITTLE UNDER 59,000 MILES ON THE TRUCK. A FEW THOUSAND MILES AGO A TECH AT THE GM DEALER LET ME KNOW THAT THEY HAD TO ADD SOME COOLANT AND IT WAS SOMETHING I SHOULD KEEP AN EYE ON. I BROUGHT THE VEHICLE BACK TO HAVE THEM LOOK INTO IT. THEY LET ME KNOW THAT THE RADIATOR HAS A SMALL LEAK. IT IS NOT BIG ENOUGH TO HAVE FLUID HIT THE GROUND IN MY GARAGE BUT IT IS LOOSING FLUID. I LOOKED ONLINE AND SAW THAT THIS IS A COMMON ISSUE. I WAS TOLD THAT IT WAS NOT COVERED UNDER WARRANTY AND IT WOULD COST A GOOD AMOUNT TO FIX. I HAVE HAD THIS VEHICLE FOR UNDER 3 YEARS AND HAVE HAD 5 ISSUES WITHOUT ANY OF THEM BEING COVERED BY WARRANTY. THIS VEHICLE SEEMS TO BE A LEMON.

TL* THE CONTACT OWNS A 2018 GMC SIERRA 1500. THE CONTACT STATED THAT WHILE DRIVING AT VARIOUS SPEEDS, THE TEMPERATURE GAUGE INDICATED THAT THE VEHICLE WAS OVERHEATED. NO WARNING LIGHT WAS ILLUMINATED. THE VEHICLE WAS TAKEN TO BECK & MASTEN BUICK GMC NORTH (11300 FM 1960 WEST, HOUSTON, TX 77065, (877) 380-8433) WHERE IT WAS DIAGNOSED AND DETERMINED THAT THE RADIATOR WAS LEAKING COOLANT AND THAT THE RADIATOR NEEDED TO BE REPLACED. COOLANT WAS REFILLED IN THE VEHICLE. THE DEALER CONTACTED THE MANUFACTURER FOR ASSISTANCE WITH REPAIRS. THE FAILURE MILEAGE WAS APPROXIMATELY 47,000.

AFTER LONG PERIODS OF RUNNING AND IDLE, VEHICLE STALLS OUT HAS A HARD TIME RESTARTING. GAS PADDLE BEING PRESS HELPS SOMETIMES. CHECK CODE P2635 PLUS OTHERS (RANDOM SECONDARY CODES), COME ON. THIS HAS TAKEN PLACE IN AZ WHERE THE AMBIENT AIR TEMPERATURE TYPICALLY IS OVER 100. VEHICLE HAS BEEN TO GM DEALER WHO SAYS ITS VAPORIZING THE FUEL IN THE LINES. TSB PIP5507B DOSE NOT INCLUDE 2018, HOWEVER THE DESIGN HASN'T CHANGED. CONDITIONS; LONG IDLE, HOT WEATHER, LOW SPEEDS UNDER 25 MPH OR IDLE. LOCATION; AZ SONRONA DESSERT, OFF-ROAD, JOBSITE, CITY STREETS.

CONDENSER ON AC LEAKING AT SAME LOCATION AS THE 2014-2017 MY. WARRANTY WAS OUT DUE TO MILEAGE BUT TRUCK IS ONLY 2 YEARS 3 MONTHS OLD. BLOWING WARM AIR WHEN AC WAS TURNED ON. *TR

FUEL INJECTION SEALS #4 O-RING SPLIT - LEAKING FUEL - POOLING GAS ON MANIFOLD. TOOK VEHICLE IN FOR SMELL OF GAS, LACK OF ACCELERATION AND POOR GAS MILEAGE. THIS IS KNOWN ISSUE BASED ON THE SERVICE BULLETIN 18-NA-137 - VEHICLE HAS LESS THAN 6000 MILES