GMC Sierra problems
293 owner complaints with NHTSA, no active recalls. Here's where owners say it breaks.
Solid reliability overall. Common issues are concentrated in a few systems.
The data says walk unless this exact vehicle has documented proof the powertrain was repaired or replaced.
- Powertrain: 115 complaints, classified severe, failures cluster 15,000–81,000 mi
- Reliability score 7.2/10 — around the segment average
Our read of the federal NHTSA complaint and recall record for this exact year and model — not a substitute for a pre-purchase inspection. How we score.
Buying a used 2018 GMC Sierra? Check these first
Here's what this model is known to do — so you can inspect for it, price it in, or make the seller fix it before you sign.
What to inspect on this specific car
- powertrain — 115 owner reports · tends to show around 47,316 mi · ~$2,500 to fix
- engine — 39 owner reports · tends to show around 69,239 mi · ~$3,100 to fix
- electrical — 30 owner reports · tends to show around 98,911 mi · ~$850 to fix
- steering — 29 owner reports · tends to show around 25,206 mi · ~$700 to fix
⚠ The one to take seriously: powertrain is flagged severe on this model , showing up around 47,316 mi. Inspect it closely on a test drive.
Recalls to confirm are done
Run the VIN from the listing — no active recalls on this model right now, but confirm none were opened after this car was built.
Verdict for buyers: 7.2/10 model. The priciest documented failure is engine (~$3,100) — get the seller's service records for it or inspect closely. Otherwise an average-risk used buy at a fair price.
We tell you what this model is known for and what to inspect — a vehicle-history report tells you what this exact car has been through. Smart buyers get both.
See the full pre-purchase inspection checklist →Ask anything about your 2018 GMC Sierra
A noise, a warning light, a repair quote, "should I buy this?" — get an answer grounded in this vehicle's actual NHTSA record, not generic advice.
Answers use this vehicle's NHTSA complaint & recall record — owner-reported and unverified, not a diagnosis. Verify anything safety-critical with a mechanic.
Top trouble spots 8 categories with 3+ complaints
Your road ahead on this 2018 GMC Sierra
When owners report each system failing, in actual miles — so you can see what's likely behind you, what's due around now, and what to budget for next. Enter your mileage to mark where you are.
- ~32,000 mipowertrain~$2,500
- ~35,750 misteering~$700
- ~37,000 mibrakes~$450
- ~59,000 miengine~$3,100
"Typical" = median owner-reported failure mileage from the NHTSA complaint record for this exact year and model. Not a maintenance schedule — a heads-up on where this model's failures cluster.
What owners are saying recent NHTSA-filed complaints · verbatim
I purchased my 2018 GMC Sierra 1500 pickup truck new in 2018. To date it only has 28K miles on it. I have never used the trailer breaking system that it came equipped with. On 12/24/22 we were traveling to a family function for Christmas. The "service trailer break system"…
After cold starts when accelerating the transmission slips from 1st to 2nd and throws your body forward. After that first gear change it doesn't do it again until another cold start. Around 34000 miles I am getting a rumbling vibration through the dash and steering wheel when…
The contact owns a 2018 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the engine temperature rose to 210 degrees and the vehicle started jerking. The contact stated that the failure also occurred while idling for a while, or while stopped at a…
My vehicle is hacked anytime I am driving the vehicle I am not in full control. The vehicle steers itself left or right while driving, the brakes are always on while driving sometimes braking harder but always on. The infotainment system has many glitches. This vehicle has been…
Estimate your repair exposure
Drag to your current mileage. Numbers are derived from this vehicle's complaint history.
Common questions
Is the 2018 GMC Sierra reliable?
Mostly yes. With a reliability score of 7.2 out of 10 based on 293 owner complaints filed with NHTSA, the 2018 GMC Sierra is generally a sound vehicle. The areas to watch are listed in the top problem section above — most are budget items, not deal-breakers.
Should you avoid the 2018 GMC Sierra?
On the NHTSA data, the 2018 GMC Sierra is one to avoid unless a specific vehicle proves otherwise. The data says walk unless this exact vehicle has documented proof the powertrain was repaired or replaced. The record behind that call: Powertrain: 115 complaints, classified severe, failures cluster 15,000–81,000 mi; Reliability score 7.2/10 — around the segment average. This is our read of the federal complaint and recall data — not a substitute for a pre-purchase inspection.
What should I check before buying a used 2018 GMC Sierra?
Inspect the powertrain first — it's the most-reported issue on this model, with 115 owner complaints filed. Typical failure occurs around 47,316 miles. Average repair cost runs about $2,500 at an independent shop. Also confirm any open recalls have been completed by running the VIN, and ask for service records covering the problem areas listed above.
Is the 2018 GMC Sierra a good used car to buy?
It scores 7.2 out of 10 on our NHTSA-based read of 293 owner complaints. The main thing to watch is powertrain. Typical failure occurs around 47,316 miles. Priced fairly and clean on inspection, it's a reasonable used buy. Our data covers what this model is known for — pair it with a vehicle-history report on the VIN to see what that specific car has been through.
What's the most common problem on the 2018 GMC Sierra?
Based on NHTSA records, the most-reported issue is powertrain, with 115 complaints filed. Typical failure occurs around 47,316 miles. Average repair cost runs about $2,500 at an independent shop.
What's the most expensive thing that goes wrong?
The powertrain is one of the costlier repair items. Average repair cost runs about $2,500 at an independent shop. Typical failure occurs around 47,316 miles. Catching early warning signs can sometimes extend life by 20–30,000 miles.
How do I check if my GMC Sierra has open recalls?
Paste your VIN into the decoder at the top of this page. We pull live from NHTSA, so you'll see exactly which campaigns apply to your vehicle and whether the dealer has logged the fix. Recall repairs are always free regardless of mileage or warranty status.
Is an extended warranty worth it on a 2018 GMC Sierra?
Math is straightforward: a quality service contract runs $1,800–3,500 over 3 years. With 293 complaints on file and the costliest repair averaging $2,500, one major failure more than pays for it. The catch is reading the contract — many providers exclude wear items and require pre-authorization, so cheaper plans are not always better value.