MAINTENANCE & FLUIDS
2015 Chevrolet Silverado 1500 Spark Plugs & Replacement
The 2015 owner manual specifies a spark plug gap of 0.037–0.043 in (0.95–1.10 mm) for all three Silverado 1500 gasoline engines.
Confirm the engine, trim, drivetrain, market and installed equipment before using a part number, capacity or repair procedure.
Spark plugs, engine codes and gap specifications
| 2015 engine | VIN engine digit | GM spark plug gap | Listed ACDelco / GM plug |
|---|---|---|---|
| 4.3L LV3 V6 | H | 0.037–0.043 in / 0.95–1.10 mm | 41-168 / GM 19459511 (verify VIN) |
| 5.3L L83 V8 | C | 0.037–0.043 in / 0.95–1.10 mm | 41-168 / GM 19459511 (verify VIN) |
| 6.2L L86 V8 | J | 0.037–0.043 in / 0.95–1.10 mm | 41-168 / GM 19459511 (verify VIN) |
Current GM parts catalogue lists 41-168 / GM 19459511 for 2015 Silverado applications. Verify engine-specific VIN fitment.
Selecting the correct plugs
The 2015 engine-specifications chart lists 0.95–1.10 mm (0.037–0.043 in) for the 4.3L LV3, 5.3L L83 and 6.2L L86. Chevrolet’s current parts catalogue lists an ACDelco 41-168 spark plug (GM 19459511) as fitting 2015 Silverado 1500 applications; validate the plug against the specific VIN and engine before ordering. Do not force a fine-wire iridium electrode when checking gap.
When to inspect or replace
A misfire, rough idle or poor acceleration may be plug-related, but the cause can also be an ignition coil, wiring, injector or mechanical fault. Inspect for oil contamination, damaged boots and abnormal deposits rather than replacing all ignition components without diagnosis.
- Disconnect ignition components only with the engine off.
- Do not force a plug into an aluminum cylinder head.
- Inspect wires or boots while replacing plugs.
When the plugs are due
The standard 2015 schedule shows spark plug replacement and wire inspection at about 97,500 miles (156,000 km). Its severe-service table shows replacement at 75,000 miles (120,000 km). Use the appropriate schedule and inspect sooner if there is a documented misfire or abnormal plug condition.
What to check while replacing spark plugs
Work on a cool engine using the correct spark plug socket and service specifications. Label and inspect plug-wire/boot positions, inspect porcelain for tracking, and start each plug by hand to avoid damaging aluminum threads. Use the GM tightening method for the exact plug and engine; no single guessed torque is safe.
A spark plug wire reference
Chevrolet’s current catalogue includes GM 12660508 / ACDelco spark plug wire for 2015 Silverado applications. That is a single listed service part, not proof of an entire engine-specific wire-set quantity. Compare the original length, terminal type and VIN.
Before changing the full set
Write down the VIN engine code and inspect the existing plugs and boots for damaged insulators, oil in a plug well and unusual deposits. If the original concern was P0300 or an individual-cylinder misfire, scan and diagnose first: injector trouble, wiring or low compression can produce similar symptoms. Fit only plugs approved for your engine and use the current GM tightening procedure.
Use the correct model-year manual and current service information. Stop if instructions or safety precautions are unclear, and use a qualified technician for work you cannot verify.
References and further reading
- Official GM 2015 Silverado Owner Manual (second printing)
- Chevrolet parts: ACDelco 41-168 / GM 19459511
- Chevrolet Parts: ACDelco spark-plug wire GM 12660508
This independent guide is not endorsed by the vehicle manufacturer. Let us know if you spot an error.