Is the GMC Sierra reliable?
49% of the 29 we inspected scored 60/100 or higher, with an average of 58/100 — it scores a little below average.
29
Cars inspectedreal pre-purchase inspections58/100
Average conditionall cars we check: 61/10049%
In good shape (60+)all cars we check: 55%Across 29 used GMC Sierras we inspected, this model scores a little below average — average condition 58/100 vs 61 for all cars we check. Every number on this page comes from real pre-purchase inspections — cars people were about to buy and paid an independent inspector to go through point by point, engine to underbody, paint depth to error codes. Not owner surveys, not warranty statistics, not forum lore: what we actually found.
What we found
Most common faults
Active error codes · Electronic equipment
45%
Tires condition & wear · Brakes and tires
38%
Oil leaks · Engine
34%
Fuel trim out of range · Engine
28%
Steering backlash · Steering (hydraulic power)
24%
Share of inspected GMC Sierras where each item was flagged.
How they score
Excellent 28%
Good 21%
Mediocre 28%
Poor 24%
Hidden history
What the seller might not mention — how often we find it on this model.
66%had a repainted or replaced panelall cars: 75%
3%showed structural repairall cars: 4%
38%had fault codes recently clearedall cars: 23%
More on GMC
Straight from recent GMC Sierra reports
2023 GMC Sierra · 36k mi — flagged: engine control module, tires condition & wear. Inspected Jul 22.
2023 GMC Sierra · 36k mi — flagged: crankcase gas pressure, battery condition, engine control module. Inspected Jul 17.
The bottom line
The Sierra's pattern is trucks that look solid until you dig into electronics and the engine bay. Active error codes hit nearly half these examples while oil leaks and fuel-trim faults pile on, so your first move is always a full OBD scan plus a cold-engine leak check before you bother with tire wear or steering play. The elevated cleared-codes rate means prior problems may have been wiped, so insist on a fresh drive cycle and walk if anything reappears. Use the tires and steering backlash as straightforward negotiation leverage only after the powertrain and electronics clear.
FAQ
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What are the most common problems on a used GMC Sierra?
The items we flag most often are active error codes (45%), tires condition & wear (38%), oil leaks (34%). Have these checked before buying.
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Should I worry about cleared fault codes?
On 38% of these cars the ECU codes had been erased shortly before sale, which can hide active faults. Ask for a diagnostic scan and start the engine from cold.
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Based on 29 inspections · updated Aug 12, 2026
