Is the GMC Sierra reliable?
52% of the 29 we inspected scored 60/100 or higher, with an average of 60/100 — it scores about average.
29
Cars inspectedreal pre-purchase inspections60/100
Average conditionall cars we check: 61/10052%
In good shape (60+)all cars we check: 53%Across 29 used GMC Sierras we inspected, this model scores about average — average condition 60/100 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 24%
Good 28%
Mediocre 31%
Poor 17%
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
Sierra buyers need to treat every truck like it might be hiding electronic and engine trouble. Codes have been cleared on 38 percent of them—far more than usual—and active error codes still light up nearly half, so start with a thorough OBD history pull and refuse any seller who won't allow it. Oil leaks and out-of-range fuel trim hit often enough that you should crawl underneath and watch for seepage while the engine runs, then negotiate or walk based on what you find. Don't skip the tires or a steering-play check either; those are the next most common weak spots.
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 1, 2026
