2017 · GMCSierra SLE Crew Cab Standard Bed
What the data shows
This 2017 GMC Sierra has accumulated 385,000 miles in roughly eight years. The L83 engine is known to be durable, but at this mileage, the transmission and engine top-end components are living on borrowed time. The asking price of $12,500 is above market for this mileage level. Budget about $12,700 over the next 12–24 months for a transmission rebuild, AFM lifter failure, and cooling system overhaul.
Green flags
- Highway Miles Likely
385k miles in ~8 years means extended highway cruising, which is less stressful on drivetrain than city miles.
- L83 Engine Longevity
the 5.3L EcoTec3 is a proven durable engine when maintained; high-mileage examples exist.
What’s costing this car points
Every car starts at 10. Each problem below takes points off. Serious and expensive problems take more, and so do problems that usually show up at about the miles this car has now.
- 6-Speed Automatic Transmission (6L80) — Impending Failure$3,500 to $5,200 to fix−4.4
- Active Fuel Management (AFM) Lifter Collapse$2,800 to $4,500 to fix−1.0
- Front Suspension & Steering Wear$1,000 to $1,800 to fix−0.4
- 4 smaller items−0.7
7.0 if the top three turn out fine. Ask the seller for repair records.
Deal Score weighs the asking price against comparable listings, the title, and the repairs documented in this guide.
- Price 32% above market
- Weak reliability (3.5/10)
Cross-referenced 3 citations across 7 findings, including 4 owner-report sources.
Detailed findings, 7 items
Click any card for the full breakdown, repair cost, and what to check. Items already handled by the owner show as checked.
Reflects the open findings; items the owner handled are excluded.
Confirm these before you buy. If you or a mechanic can verify them, that clears the car instead of ruling it out.
6-Speed Automatic Transmission (6L80) — Impending Failure
The 6L80 transmission commonly experiences torque converter failure and internal wear between 150,000 and 200,000 miles. At 385,000 miles, if the unit is original and has not been rebuilt, it is well beyond its expected service life and at imminent risk of failure.
Costly repairs, but not urgent to verify before you buy. Price them out and use them to negotiate.
Active Fuel Management (AFM) Lifter Collapse
The L83 5.3L engine uses AFM to deactivate cylinders. The lifters can collapse, especially in high-mileage examples. This often causes a loud ticking noise, misfire codes (P0300 series), and can damage the camshaft if not addressed immediately.
Air Conditioning Condenser Leak
GM truck condensers from this generation (2014–2018) are known to develop leaks at the weld seams where the condenser meets the brackets. This leads to a gradual loss of refrigerant and ultimately no cold air.
Cooling System Overhaul (Radiator, Water Pump, Hoses)
Plastic-tanked radiators and water pumps have a finite lifespan and are prone to cracking, leaking, or bearing failure usually between 120,000 and 180,000 miles. High heat cycles at 385,000 miles put the entire cooling system at high risk of failure.
Front Suspension & Steering Wear
The independent front suspension (IFS) on K2XX trucks wears out lower ball joints, control arm bushings, and inner tie rod ends. At 385,000 miles, if these components are original, they are guaranteed to be clunking, loose, or dangerously worn.
High-Pressure Fuel Pump (HPFP) and Injector Wear
Gasoline Direct Injection (GDI) on the L83 relies on a high-pressure fuel pump and sensitive injectors. High mileage can cause carbon buildup on intake valves (a known GDI issue) and wear in the HPFP, leading to long crank times, rough idle, and stalling.
Minor wear typical for the car’s age. Not worth negotiating over, but good to track as an owner.
Engine Oil Consumption and Rear Main Seal Leak
L83 engines, even non-AFM deactivated ones, can consume oil (1 quart per 1,000–2,000 miles is common). High mileage also stresses the rear main seal (RMS), which can cause a significant oil leak between the engine and transmission.
Every finding still open carries a question worth asking. Copy them as one message, already ordered by severity. Anything you have marked above drops off on its own.
Price & negotiation
BetaBased on comparable listings and the repairs you can document. A starting point for what this car should cost.
Price breakdown
What it costs, and when
Verify now
Critical and major items to confirm first.
Possible year-one expense
Caution items with repair-cost context.
Each range is what that one item costs if it turns out to be present. Not every item will apply to this car, so they do not add up to a bill. Verify with a mechanic.
Asking is $12,500 against a typical $9,500 for this car and mileage. The work is the difference, not the sticker.
Negotiate your offer
At asking, this is about 32% above the market estimate (about $3,000). The documented repairs below are the kind of evidence buyers cite to start lower.
- Documented critical/major repairs of $9,300–$16,100 you can point to.
- Strongest items to raise first: 6-Speed Automatic Transmission (6L80) — Impending Failure, Active Fuel Management (AFM) Lifter Collapse.
Pricing is in beta. The market estimate comes from research models and can be off by thousands on the same car, so check recent local listings before you rely on it. This is information to help you research, not a professional inspection, an appraisal, or financial advice.
Recalls & safety
NHTSA crash-test ratings and recall data for this make, model, and year. Check recall status with your VIN before buying.
In-person inspection
7 things to check before you buy
5 major and 1 caution findings, turned into a walkthrough for the driveway. Try it on this sample.
Before you leave: Ask the seller not to start or move the car before you arrive. A sales-ready car has usually been warmed up, and a warm engine hides the startup smoke, rattles and rough idle that the first section is built around.
Everything on this list is what you can see standing next to the car. A shop on a lift sees the rest, and a written pre-purchase inspection listing parts and labor is what a seller has to answer to. Budget roughly $100 to $150 at an ASE-certified shop.
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