Chevrolet S10 Spark Plug Replacement Guide for 1987-1993
Get your S10 running smoothly with the right new spark plugs for your engine.
- Many S10 owners find their trucks run best on standard copper ACDelco or NGK plugs, even though they require more frequent changes.
- Replacing spark plug wires at the same time as the plugs is crucial for reliable performance.
- On V6 engines, be prepared for a tight squeeze on some plugs; accessing them through the wheel well can help.
- Always check and adjust the spark plug gap before installation, as it varies by engine and is critical for performance.
Symptoms of Failing Spark Plugs in an S10
When your S10's spark plugs are worn out, you'll likely notice. The signs can start small but will worsen over time. Common symptoms include a rough idle where the truck shakes or sputters, engine misfires, and a noticeable drop in fuel economy. You might also experience sluggish or poor acceleration, making the truck feel weak. In some cases, a check engine light may appear, with codes like P0300-P0306 indicating a misfire in one or more cylinders. If you hear engine knocking or pinging, it's a serious sign that the plugs need immediate attention to prevent engine damage.
🎬 Watch a detailed breakdown of common bad spark plug symptoms.Choosing the Right Aftermarket Spark Plugs
For the 1987-1993 S10, you have several reliable aftermarket spark plug options. The original factory plugs are ACDelco, and they remain a solid choice. However, many owners have great success with aftermarket brands, especially NGK, which is often considered an OEM-equivalent and may even manufacture some ACDelco plugs.
Brand Quality Tiers for 1987-1993 Chevrolet S10
| Tier | Brands | Assessment |
|---|---|---|
| Top Tier (OEM or Better) | ACDelco, NGK, Denso | ACDelco is the original equipment manufacturer and a trusted choice. NGK and Denso are highly regarded for their quality and reliability, with many owners reporting excellent performance in their S10s. Some S10s run best on simple, conventional copper plugs like the original ACDelco R42LTS. |
| Mid-Tier (Reliable Aftermarket) | Bosch, Autolite | Bosch and Autolite offer a good balance of performance and value. They are dependable choices for daily driving and are widely available. Some owners have used Bosch platinum plugs with no issues. |
| Performance-Oriented | MSD, Accel | These brands are geared towards modified engines or owners seeking a potential performance edge. For a stock 2.5L, 2.8L, or 4.3L engine, these are generally not necessary but are a quality option. |
| Economy | Champion | Champion plugs are a budget-friendly option for basic maintenance. While functional, some owners prefer to stick with ACDelco or NGK for better long-term reliability. |
A Note on Plug Material: Copper vs. Iridium/Platinum
While modern iridium and platinum plugs last longer, many S10 owners find their trucks run best on traditional copper-core plugs, similar to what they came with from the factory. Some have even reported misfires after switching to iridium plugs, which were resolved by going back to copper ACDelcos. Copper plugs are less expensive but need to be changed more frequently, typically every 30,000 miles.
Known Issues, Recalls, and TSBs
No recalls or Technical Service Bulletins (TSBs) specifically for spark plug failure were found for the 1987-1993 Chevrolet S10. Issues with spark plugs on these trucks are almost always related to normal wear and tear. However, it's important to note that a persistent misfire on a single cylinder, even after changing the plug, could point to a bad spark plug wire or a more serious internal engine issue.
Installation Pro-Tip
On V6 models (2.8L and 4.3L), some spark plugs can be difficult to reach, particularly the one near the steering shaft on the driver's side. Accessing it through the wheel well after removing the tire can make the job much easier. Always apply a small amount of anti-seize compound to the new plug's threads to prevent them from getting stuck in the cylinder head, and use dielectric grease inside the plug wire boot for a good seal.
Frequently Asked Questions (FAQ)
What is the correct spark plug gap for my S10?
The correct gap can vary by engine. For the 2.5L 4-cylinder, a common gap is 0.060 inches. For the 4.3L V6, it can be 0.035 or 0.045 inches depending on the specific year and ignition system. Always verify the specification for your exact engine, often found on a sticker in the engine bay, and check the gap on new plugs before installation.
Should I replace my spark plug wires at the same time?
Yes, it is highly recommended. Old or failing spark plug wires can cause misfires and prevent your new plugs from performing correctly. Replacing the plugs and wires together as a set ensures the entire ignition system is refreshed.
🎬 See a full tune-up guide for 1982-1993 S10 models.How often should I change the spark plugs on my 1987-1993 S10?
For standard copper plugs, a good interval is every 30,000 miles. If you opt for longer-life platinum or iridium plugs, you can extend that interval, but be aware that some of these older engines perform best with the more frequent changes of basic copper plugs.
Do I need special tools to change my spark plugs?
You will need a ratchet, a spark plug socket (usually 5/8-inch), an extension, and a spark plug gap tool. A torque wrench is recommended for proper tightening. For V6 models, a universal joint or swivel socket can be very helpful for reaching angled plugs.
🎬 Follow this step-by-step video to replace your plugs and wires.Helpful Videos
Technical Specifications
OEM Part Numbers: R42LTS CR43TS
Spark Plug Gap: Varies by engine (e.g., 0.035", 0.045", 0.060"). Socket Size: 5/8 inch. Plug Material: Originally Copper Core.
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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.
- Chevrolet S10:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Symptoms of Failing Spark Plugs in an S10
- Choosing the Right Aftermarket Spark Plugs
- Brand Quality Tiers for 1987-1993 Chevrolet S10
- A Note on Plug Material: Copper vs. Iridium/Platinum
- Known Issues, Recalls, and TSBs
- Installation Pro-Tip
- Frequently Asked Questions (FAQ)
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