You’ve invested in a powerful GMC with a 6.2L V8 engine, but now you’re hearing concerning noises or experiencing performance issues. With hundreds of thousands of these engines facing serious problems, it’s crucial to understand what you might be dealing with and how to protect your investment.
Catastrophic Bearing Failures and the Major Recall
The GMC 6.2L V8 engine has become notorious for serious bearing and crankshaft failures that can leave you stranded without warning. In April 2025, General Motors issued Safety Recall N252494001 covering approximately 597,630 vehicles in the United States alone.
Which Vehicles Are Affected?
The recall specifically targets 2021-2024 model year vehicles with the 6.2L V8 L87 engine:
- GMC Sierra 1500
- GMC Yukon
- GMC Yukon XL
What Causes These Failures?
Manufacturing defects at GM’s St. Catharines plant between March 2021 and May 2024 created a perfect storm of problems:
- Improper surface finishes on connecting rods
- Out-of-specification tolerances
- Contamination during the machining process
These issues lead to rod bearing damage that can destroy your engine with little warning.
Warning Signs to Watch For
If you notice any of these symptoms, get your vehicle checked immediately:
- Sudden engine knocking or banging sounds
- Check engine light (especially with code P0016)
- Engine hesitation or misfires
- Abnormal shifting
- Reduced power
- Complete no-start conditions
When bearings fail catastrophically, you’ll often experience complete loss of propulsion while driving, creating significant safety risks.
The Recall Solution
GM’s recall remedy includes:
- Engine inspection
- For passing engines: switch to higher-viscosity 0W-40 oil, new oil cap, replacement filter
- For failing engines: complete engine replacement
The bad news? GM estimates about 18,000 engines will need full replacement, costing over $10,000 each. Worse yet, many owners are waiting 6-16 weeks for replacement engines due to supply shortages.
Lifter Failures: The AFM/DFM Nightmare
Beyond the bearing failures, GMC’s 6.2L engines suffer from widespread lifter problems linked to their cylinder deactivation systems.
Active Fuel Management vs. Dynamic Fuel Management
These fuel-saving technologies use collapsible lifters to deactivate cylinders:
- AFM (earlier models): Switches between 8 and 4 cylinders
- DFM (2019+): Can operate in 17 different cylinder patterns
While innovative, these systems have proven highly problematic in real-world use.
How to Identify Lifter Failures
Look for these telltale signs:
- Persistent ticking or knocking noises
- Misfires (especially during acceleration)
- Rough idling
- Check engine light with P0300 series codes
- Reduced performance
Failed lifters can cascade into more serious damage, including bent pushrods and damaged camshafts. Repair costs typically range from $4,000 to $8,000 depending on the extent of damage.
The DFM Delete Solution
Many owners choose to eliminate the problematic DFM system altogether:
- Tuning-only solutions ($200-$500): Disable DFM via software
- Complete physical removal ($2,000-$4,000): Replace collapsible lifters with conventional solid lifters
While not covered under warranty, these modifications can prevent future failures in otherwise reliable engines.
Oil Consumption and Pressure Problems
The 6.2L engine’s oil-related issues compound its other problems, creating a perfect storm of reliability concerns.
Why Your GMC Drinks Oil
Many owners report using 1-2 quarts between oil changes, far exceeding normal consumption. This happens because:
- Worn piston rings allow oil into combustion chambers
- Degraded valve seals permit oil seepage
- Oil passes through the AFM/DFM hydraulic circuits
GM considers consumption up to one quart per 2,000 miles “normal,” but this excessive consumption stresses the engine and contributes to carbon buildup problems.
Complex Oil Delivery System
The L87 engine uses a two-stage variable oil pump and complex oil circuits to support the DFM system. This complexity creates vulnerability:
- Pressure irregularities contribute to both lifter and bearing failures
- The additional demands of DFM hydraulic circuits can cause pressure drops
- Malfunctioning oil pressure relief valves lead to inadequate lubrication
Carbon Buildup: The Direct Injection Downside
All GMC 6.2L engines use direct injection technology, which sprays fuel directly into combustion chambers rather than over intake valves. While efficient, this design creates a significant problem.
Why Carbon Accumulates
Without fuel washing over intake valves, carbon deposits build up over time:
- Oil vapors from the PCV system bake onto valve surfaces
- Direct injection provides no cleaning mechanism for intake valves
- Carbon accumulation restricts airflow and affects valve seating
The result? Severe cold-start misfires and rough running, especially in cold weather.
Signs of Carbon Buildup
Watch for these symptoms:
- Hard starting, especially in cold weather
- Rough idle that smooths out as the engine warms
- Persistent misfires across multiple cylinders
- Check engine light with misfire codes
- Reduced power and efficiency
Professional cleaning using walnut blasting typically costs $300-$800 but may need repeating every 60,000-80,000 miles.
Model Years to Avoid vs. Better Options
Not all GMC 6.2L engines are created equal. Some model years have proven significantly more problematic than others.
Highest Risk: 2021-2024 Models
These years face the highest risk due to:
- Bearing failure recall affecting these specific model years
- Manufacturing defects from the St. Catharines plant
- Multiple reports of catastrophic failures at low mileage (under 20,000 miles)
Moderate Risk: 2019-2020 Models
These years represent a middle ground:
- Introduced the more complex DFM technology
- Some bearing problems reported, but at lower rates
- Still vulnerable to lifter failures
Lower Risk: 2015-2018 Models
The 6.2L L86 engine (predecessor to the L87) generally shows better reliability:
- Used simpler AFM system instead of DFM
- Manufactured before supplier changes that contributed to bearing problems
- Fewer reports of catastrophic failures
2025 Models: Too Soon to Tell
The 2025 model year is excluded from the bearing failure recall, suggesting GM has addressed manufacturing defects. However, insufficient time has passed to evaluate long-term reliability.
Diagnostic Codes That Signal Trouble
When your check engine light illuminates, certain diagnostic codes are red flags for GMC 6.2L engines.
Critical Codes to Watch For
| Code | Description | What It Usually Means |
|---|---|---|
| P0016 | Crankshaft/Camshaft Position Correlation | Bearing damage or timing chain problems – specifically mentioned in recall documentation |
| P0300 | Random Multiple Misfires | Often lifter failures or carbon buildup |
| P0301-P0308 | Cylinder-specific misfires | Typically indicates which cylinder has a failed lifter |
| P0011/P0021 | Camshaft Position Timing Over-Advanced | Oil pressure or VVT solenoid issues |
These codes should prompt immediate professional diagnosis, especially P0016, which often indicates imminent engine failure.
Preventive Maintenance Strategies
While many issues stem from design and manufacturing flaws, proper maintenance can help minimize risks.
Oil Management Best Practices
Aggressive oil maintenance is crucial for these engines:
- Use high-quality full synthetic oil
- Change oil every 3,000-5,000 miles (more frequently than GM recommends)
- Switch to 0W-40 viscosity oil as specified in the recall
- Use premium filters with superior check valves
- Monitor oil level frequently between changes
Managing DFM System
For vehicles not experiencing problems yet:
- Consider aftermarket tuning to disable DFM (may affect warranty)
- Use OBD-II port devices that prevent cylinder deactivation without permanent modifications
- For out-of-warranty vehicles, complete AFM/DFM delete kits provide the most reliable solution
Reducing Carbon Buildup
While you can’t eliminate carbon buildup in direct injection engines, you can minimize it:
- Use high-quality fuels with detergent additives
- Add fuel system cleaners every 5,000-10,000 miles
- Consider Italian tune-ups (occasional high-RPM driving) to help clear deposits
- Schedule valve cleaning service at 60,000-mile intervals
Repair Costs: What to Expect
If your GMC 6.2L engine does develop problems, repair costs can be substantial.
| Issue | Average Cost | Notes |
|---|---|---|
| Complete Engine Replacement | $10,000-$15,000 | Covered under recall for 2021-2024 models with bearing failures |
| Single-Bank Lifter Replacement | $4,000-$6,600 | Not covered by recall, may be under powertrain warranty |
| Complete Lifter Replacement | $7,000-$9,000 | Both banks of lifters plus related components |
| DFM Delete Kit & Installation | $2,000-$4,000 | Preventive measure for out-of-warranty vehicles |
| Carbon Cleaning (Walnut Blast) | $300-$800 | Recommended every 60,000-80,000 miles |
For vehicles still under warranty, GM’s 5-year/60,000-mile powertrain coverage should address many of these issues, but the warranty process can be lengthy, especially with current parts shortages.
Legal Options for Repeated Problems
If your GMC with the 6.2L engine has experienced multiple repair attempts, you may have legal recourse under state lemon laws or federal warranty protection.
The Magnuson-Moss Warranty Act provides protection when:
- Your vehicle has been in for repairs multiple times for the same issue
- The problem substantially impairs the use, value, or safety of your vehicle
- The manufacturer has been given reasonable opportunities to fix the problem
Many owners have pursued lemon law claims for GMC 6.2L engine problems, particularly for the 2021-2024 models affected by the bearing failure recall.
Real-World Owner Experiences
Owner reports from forums and social media reveal the real impact of these engine problems:
“My 2022 Sierra with the 6.2 failed catastrophically at 18,742 miles. Complete engine replacement took 14 weeks due to parts shortages. Dealer provided a loaner for only the first month.” – At4Forum member
“After my third lifter failure, I had a DFM delete kit installed at my own expense. 40,000 miles later, no more issues. Best $3,200 I ever spent on the truck.” – Reddit user
“Carbon buildup caused persistent misfires every winter. After walnut blasting at 65,000 miles, it runs like new again.” – TrailBoss.org member
Future Outlook for the 6.2L Engine
General Motors appears to be addressing some of the 6.2L engine’s problems, but questions remain about long-term reliability.
For 2025 models, GM has made manufacturing changes at the St. Catharines plant and implemented quality control improvements. However, the fundamental design elements that contribute to lifter failures and carbon buildup remain unchanged.
Industry analysts suggest that while the catastrophic bearing failures may be resolved, the inherent complexity of the DFM system will continue to present reliability challenges throughout the engine’s lifecycle.
Until GM completely redesigns its V8 architecture or abandons cylinder deactivation technology, the 6.2L engine will likely continue to require more maintenance and face more reliability issues than competing engines from other manufacturers.
