This informational bulletin explains the difference in AFM and DFM engines and what is and is not activated during this occurrence.
full bulletin at NHTSA ↗2017 GMC Sierra engine problems
moderate 40 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Failure mileage
Complaints
40
Recalls
0
Avg fix
$3,100
What stands out
Owners have filed 40 engine complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Bulletin provides graphics, information and guidelines for engine component wear to assist service personnel as a guideline to perform necessary engine repairs and prevent unnecessary engine replacement.
full bulletin at NHTSA ↗This informational bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
full bulletin at NHTSA ↗This Preliminary information communicates to the technician the need to inspect the induction system for potential icing issues in very cold ambient temperatures. To allow the ice to melt so that it can be drained from the related components. That any of the listed DTC's may set with or without poor engine performance.
full bulletin at NHTSA ↗This Preliminary information communicates to the dealer additional information on checking for the engne crankcase being overfull on oil causing an engine vibration concern. The technician is advised to inspect for contaminnants and adjust the engine oil level as needed.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2017 GMC Sierra's gasoline engines are suffering multiple chronic failures, starting with lifter and pusher-rod collapse. Owners report ticking or tapping noises, loss of power, misfires, and stalled vehicles between 48,000 and 127,000 miles. The problem cascades quickly—initial lifter replacement ($7,000–$8,500) escalates to camshaft damage, bent pushrods, and cylinder head harm within weeks, often forcing full engine replacement at $14,000–$22,000. Owners and mechanics attribute this to the active fuel management system (V8-to-V4 cylinder deactivation), and a class action lawsuit is underway, though no formal recall exists.
Fuel injectors fail unpredictably at 15,000 to 59,000 miles despite dealer maintenance, with all eight injectors sometimes reading out-of-tolerance simultaneously. Repair cost runs $2,700 per incident. GM's Service Bulletin DCS5097 (July 2019) offers inconsistent regional coverage.
Radiator leaks appear at 55,000 to 130,000 miles, and coolant warning lights malfunction, displaying low-level alerts with the reservoir full—risking driver complacency in genuine low-coolant situations.
The 6.2L engine exhibits unexplained, persistent vibration at all temperatures and speeds, severe enough to see in a water glass, yet dealerships insist it is normal design.
Exhaust manifold studs break, letting fumes into the cab, and electrical gremlins including radio and Bluetooth malfunctions have occurred. One brand-new truck (under 700 miles) exhibited severe misfire with a trouble code the dealer could not resolve.
Same GMC Sierra engine reports on nearby years: 2014 · 2015 · 2018 · 2019 · 2020
Failure modes owners describe
Lifter and pusher rod failure (active fuel management system)
Owners report sudden ticking or tapping noises from the engine, loss of power, misfire codes, and stalled vehicles. Diagnostics reveal collapsed lifters, bent pushrods, damaged camshafts, and worn camshaft bearings. Multiple owners cite the active fuel management system (cylinder deactivation from 8 to 4 cylinders) as the root cause. Repairs have escalated from lifter replacement to full engine replacement.
When: 48,000 to 126,581 miles; some failures occur shortly after purchase; repeated failures within weeks of dealer repair
Symptoms owners cite: Ticking or tapping noise from engine; Loss of engine power; Misfire, hesitation, rough running; Engine shuddering or vibration; Vehicle stalls or shuts down while driving at highway speeds; Check engine light illuminated
Codes mentioned: PO300, Cylinder misfire codes
Repairs/costs cited: Initial repairs: lifter and pusrod replacement ($7,136 reported). Escalations: camshaft and cylinder head damage requiring top-end rebuild or full engine replacement ($14,350–$22,000 reported). One owner reported $8,500 for complete top end rebuild after 6.2L lifter and camshaft failure.
Recalls/TSBs owners mention: GM has issued Service Technician reports on the issue but no formal recall. A class action lawsuit has been filed. One owner cited NHTSA Campaign 25V274000 (Engine and Engine Cooling) as potentially related, but the VIN was not included.
Fuel injector failure
Owners report check engine lights with trouble codes indicating fuel injector out-of-tolerance or fuel/air ratio problems. Typically occurs at low mileage. Dealerships have confirmed multiple vehicles with identical issues. GM issued Service Bulletin DCS5097 (Special Coverage Engine Fuel Injector) on July 26, 2019, but coverage is inconsistent by region.
When: 25,000 to 58,786 miles; some failures occur early in ownership or after prior sensor replacements
Symptoms owners cite: Check engine light illuminated; Vehicle runs rough or hesitates; Shuddering or vibration while driving; Engine misfire
Codes mentioned: 219a (fuel/air ratio problem), All 8 fuel injectors out of tolerance
Repairs/costs cited: Fuel injector replacement costing approximately $2,700 reported. In one case, fuel cell pressure sensor replacement preceded injector failure by two weeks ($700). One owner reported five injector replacements within three years at 15,000 miles.
Recalls/TSBs owners mention: Service Bulletin DCS5097 issued July 26, 2019, but regional coverage gaps exist. No formal recall issued as of complaint dates. GM customer assistance unable to provide adequate information on parts availability or delays.
Crankshaft and crankbearing clearance defect (engine rebuild issue)
Owner rebuilding a high-mileage L86 engine discovered inadequate clearance between OEM bearings and OEM crankshaft, causing bearing failure after 10,000 miles. Research revealed the L86 and L87 (subject of current recall) share the same crank part number. Afters econd rebuild with aftermarket bearings to achieve correct clearance, truck runs properly. Suggests systemic clearance issue in both engine families.
When: 250,000+ miles (initial failure); discovered during rebuild
Symptoms owners cite: Engine failure after rebuild at 10,000 miles; Crank bearings and new crankshaft damaged after short operation
Repairs/costs cited: First rebuild lasted 10,000 miles before crank bearing failure. Second rebuild required purchase of aftermarket crank bearings to match correct clearance specs. Second new GM crankshaft also failed due to same clearance issue.
Recalls/TSBs owners mention: No response documented. Owner independently identified that GM replaced L86 crankshaft specs with L87 crank, both sharing same part number despite clearance differences.
Exhaust manifold stud failure
Owners report broken or missing exhaust manifold studs, typically on the driver's-side rear or back cylinder. Breakage allows exhaust manifold to leak, causing exhaust fumes to enter the cab and creating loud ticking or chirping sounds on cold start.
When: Low mileage (one at oil change service); another observed after cold start deterioration over months
Symptoms owners cite: Broken or missing exhaust manifold studs; Exhaust fumes entering the cab; Chirping or ticking sound on cold start; Smell of oil fumes or exhaust gas
Repairs/costs cited: Stud replacement required. One owner noted dealership did not identify the issue during routine service visit.
Radiator leak and coolant issues
Multiple owners report radiator leaks requiring replacement, typically at moderate mileage. One owner notes the issue appears similar to documented 2014–2015 model-year radiator failures. Another reports repeated false coolant-low warning lights despite full coolant level, causing concern about driver ignoring genuine low-coolant alerts. Mechanics acknowledge this is a known fleet-wide problem.
When: 55,000 to 130,000 miles
Symptoms owners cite: Radiator crack or leak; Antifreeze odor detected; Coolant warning light illuminated repeatedly despite full level; Loss of coolant when engine is hot
Repairs/costs cited: Radiator replacement required (cost not specified in narratives). One owner reported high chance of driver resetting warning light if genuinely low due to false-alarm fatigue.
Recalls/TSBs owners mention: In one case, manufacturer informed dealer that owner must pay for radiator replacement despite known manufacturing issue.
Engine vibration (6.2L)
Owner of premium 6.2L engine reports vivid, persistent engine vibration at all temperatures, altitudes, and gear positions—visible enough to shake water in a glass on the dashboard. Both dealerships and GM corporate confirmed this is normal design for the 6.2L engine and refused further investigation since no diagnostic code was present.
When: Shortly after purchase; persistent across all operating conditions
Symptoms owners cite: Vivid and persistent engine vibration; Vibration at all engine and ambient temperatures; Vibration noticeable even in Park or Neutral; No associated check engine code
Repairs/costs cited: No repair offered. GM corporate stated truck is running as designed.
Recalls/TSBs owners mention: Two dealerships and GM corporate (SR# 8-3108393XXX) confirmed the vibration is per normal design for 6.2L. GM declined further resolution.
Knock sensor failure
Vehicle entered limp mode at 209,000 miles with no warning light, diagnosed with knock sensor failure by independent mechanic.
When: 209,000 miles
Symptoms owners cite: Vehicle enters LIMP Mode; No warning light illuminated prior to failure
Repairs/costs cited: Knock sensor replacement required (cost not specified).
Misfire and rough running with no initial diagnosis (PIP5457B)
Vehicle with under 700 miles exhibited severe misfire, chugging, jerking, and hesitation during acceleration. Dealer identified code PIP5457B but stated no known cause, repair, or corrective code exists. Owner reports near-accident on highway due to lurching during merge; vehicle dangerous to drive.
When: Under 700 miles (new vehicle)
Symptoms owners cite: Misfire and hesitation on acceleration; Chugging and jerking motion; Rough running; Transmission sputtering; Loss of power on hills or during merges; Dangerous driving behavior
Codes mentioned: PIP5457B
Repairs/costs cited: Dealer stated no known repair exists.
A/C condenser pinhole leak
Owner reports pinhole leak in A/C condenser, noting it appears to be a systemic problem affecting multiple GM vehicles using the same parts.
When: Unknown mileage
Symptoms owners cite: Pinhole leak in A/C condenser
Synthesized from 40 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had engine trouble with your 2017 GMC Sierra?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2017 GMC Sierra?
It's a documented issue but not catastrophic. 40 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 17 complaints that reported odometer mileage, most engine failures cluster between 39,000 and 99,700 miles, with the median around 60,000. A quarter of owners report trouble before 39,000; a quarter make it past 99,700. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2017/GMC/Sierra.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.