A Guide to Spark Plugs for the 2015-2019 Chevrolet Corvette
Keep your Corvette's high-performance engine firing on all cylinders with the right set of spark plugs.
- Stick with the OEM ACDelco iridium plugs or high-quality aftermarket brands like NGK and Denso for the best performance and reliability.
- Engine misfires can be caused by a simple loose spark plug wire at the coil; check this before starting a full replacement.
- The passenger-side plugs are difficult to access and may require moving the fuse box to reach them.
- Always check the spark plug gap before installation, even if the plugs are sold as pre-gapped.
Is Your Corvette Showing Signs of Bad Spark Plugs?
Worn or fouled spark plugs can cause noticeable issues with your Corvette's performance. If you experience any of these symptoms, it might be time for a replacement. 🎬 Watch this guide on common symptoms of bad spark plugs. A check engine light, especially with misfire codes (P0300-P0308), is a common indicator.
- Rough Idling: The engine may shake or vibrate more than usual when the car is stopped.
- Engine Misfires: You might feel a hesitation or stumble during acceleration as a cylinder fails to fire correctly.
- Reduced Power: The car may feel sluggish and less responsive than normal.
- Worse Fuel Economy: Inefficient combustion means you'll be visiting the gas station more often.
- Difficulty Starting: Weak plugs can struggle to create the initial spark needed to start the engine.
Known Issues and Technical Service Bulletins (TSBs)
While there are no specific recalls for spark plugs on the 2015-2019 Corvette, General Motors issued a Preliminary Information bulletin (PIP5159C) regarding engine misfires. This bulletin notes that a loose spark plug wire connection at the ignition coil can cause misfire codes (P0300-P0308). The cause is often a missing or damaged "C" clip on the wire end. Before replacing plugs for a misfire, it's wise to check that all plug wires are securely fastened at both ends.
🎬 See how a loose wire caused a P0300 misfire code.Choosing the Right Aftermarket Spark Plugs
When shopping for new spark plugs, you have several options. The original equipment (OEM) plugs are made by ACDelco, but high-quality aftermarket brands can offer similar or even better performance. Most modern plugs for the Corvette use an iridium tip, which offers a long service life and excellent performance.
Aftermarket Brand Tiers
| Tier | Brands | Quality & Performance Notes |
|---|---|---|
| OEM / Premium Aftermarket | ACDelco, NGK, Denso | ACDelco is the factory-installed brand, offering reliable, proven performance. NGK and Denso are highly respected Japanese brands often considered equivalent or an upgrade to OEM, known for their quality and use in high-performance applications. Many Corvette owners on forums recommend NGK as a top choice. |
| Reputable Aftermarket | Bosch, Champion | Bosch and Champion are well-known brands that produce quality iridium and platinum plugs. They are a solid choice for owners looking for a balance of performance and value, though some forum users have mixed opinions compared to ACDelco or NGK. |
| Budget-Friendly | Skyward | Budget-friendly brands can offer significant cost savings. While they may meet basic specifications, their long-term durability and performance consistency may not match that of premium brands. These are best suited for owners on a tight budget. |
Pro Tip: Check the Gap! Even if plugs are advertised as "pre-gapped," it's crucial to verify the gap with a feeler gauge before installation. The correct gap ensures the strongest spark for your engine. Shipping and handling can sometimes alter the gap.
Frequently Asked Questions
When should I replace my Corvette's spark plugs?
While some general sources suggest intervals as low as 30,000 miles, the original iridium spark plugs in a C7 Corvette are designed for a long life. Many modern plugs can last up to 100,000 miles under normal conditions. However, if you are experiencing symptoms of failure, they should be replaced regardless of mileage.
Is it difficult to change the spark plugs myself?
Changing the spark plugs on a C7 Corvette is a feasible DIY project for those with some mechanical experience, but it requires patience. The driver's side is relatively straightforward, but the passenger side is tight. To access the rear plugs on the passenger side, you will likely need to move the fuse box and possibly the coolant reservoir. A good set of tools, including various extensions and swivel sockets, is essential.
🎬 Follow this step-by-step video to change your C7 spark plugs.What is the difference between Iridium and Platinum plugs?
Iridium and platinum are precious metals used on the spark plug's electrodes. Iridium has a higher melting point and is harder than platinum, which generally allows for a longer lifespan and more consistent performance. Most OEM and high-quality aftermarket plugs for the C7 Corvette are iridium.
Should I replace the spark plug wires at the same time?
It is a good practice to replace the spark plug wires when you replace the plugs, especially if they are original and have high mileage. Wires can degrade over time, increasing electrical resistance and delivering a weaker spark. Also, check the connection at the coil, as loose wires are a known issue that can mimic bad spark plugs.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12622441 41-114 12681656 41-128
The 2015-2019 Corvette uses iridium spark plugs. The specific part number can vary between the base LT1 engine and the supercharged LT4 (Z06) or LT5 (ZR1) engines. Always confirm the correct part number for your specific model. The plugs typically come pre-gapped, but it is best practice to verify.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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