A Guide to Spark Plug Replacement for the 2007-2008 Isuzu i-290
Keep your 2.9L engine running smoothly with the right set of new aftermarket spark plugs.
- The 2007-2008 Isuzu i-290 is a rebadged Chevy Colorado; parts and procedures are identical.
- Use high-quality Iridium spark plugs, such as the OEM AC Delco 41-103, NGK, or Denso for best results.
- Iridium plugs are pre-gapped and should not be adjusted to avoid damaging the fragile electrode tip.
- Replacement is a simple DIY job that can be done in about an hour with basic tools.
Signs of Failing Spark Plugs
When your i-290's spark plugs are nearing the end of their life, you'll likely notice a few performance issues. Because this truck shares its engine with the Chevy Colorado and GMC Canyon, the symptoms are well-documented. You might experience a rough idle, hesitation during acceleration, a noticeable drop in fuel economy, or difficulty starting the engine. The most direct sign is a flashing or steady Check Engine Light on your dashboard, often with codes indicating a cylinder misfire (P0300, P0301, P0302, P0303, P0304).
🎬 Watch: Diagnosing a P0300 misfire code on this engineA More Serious Problem
In some cases, the 2.9L engine family can suffer from worn valve seats, which causes a loss of compression and leads to misfires. If new spark plugs and ignition coils do not solve a persistent misfire code, it is recommended to have a professional mechanic perform a compression test to rule out a more serious internal engine issue.
Choosing the Right Aftermarket Spark Plugs
Your Isuzu i-290 came from the factory with AC Delco Iridium spark plugs (part number 41-103), which are considered the original equipment (OEM) benchmark. When shopping for aftermarket replacements, choosing a plug that meets or exceeds these OEM standards is the best approach.
Brand Quality Tiers
- OEM-Equivalent (Best Choice): AC Delco is the original GM parts supplier for your truck. Choosing their 41-103 Iridium plug is the safest bet for factory performance and longevity. NGK and Denso are also top-tier Japanese brands known for making high-quality iridium plugs that are excellent alternatives to OEM.
- Quality Aftermarket: Brands like Bosch and Champion offer iridium and platinum plugs that are a good value. They are reliable replacements for daily driving. However, some owners in forums have noted potential issues when using platinum plugs in engines not originally equipped with them. Sticking with iridium is recommended.
- Performance: MSD is a brand focused on high-performance ignition systems. While available, their plugs are generally not necessary for a stock 2.9L engine and are better suited for modified vehicles.
- Budget-Friendly: Brands like Autolite and Skyward offer more affordable options. While functional, they may not offer the same lifespan or performance consistency as the premium iridium plugs.
Stick with Iridium
The original plugs are iridium for a reason: they provide a long service life (up to 100,000 miles) and a consistent, strong spark. Iridium plugs come pre-gapped from the factory and should not be adjusted, as the fine-wire tip is fragile and can be easily damaged. Always verify the part number is correct for your truck before installing.
Spark Plug Replacement Cost for 2007-2008 Isuzu i-290
| Part Type | Price Range (4 Plugs) |
|---|---|
| New Aftermarket (Iridium) | $22.80 - $83.24 |
| New OEM (AC Delco 41-103) | $40 - $65 |
| Shop Labor | $100 - $150 |
Cost estimates are approximate and can vary based on location and supplier. 🎬 See more on bad spark plug symptoms and costs
Frequently Asked Questions
Is replacing the spark plugs on an i-290 a difficult job?
No, it is considered an easy DIY job that takes about an hour. It requires basic hand tools, including a 10mm socket for the ignition coil bolts and a 5/8" spark plug socket with an extension. The coils and plugs are easily accessible after removing the plastic engine cover.
🎬 Watch this step-by-step spark plug replacement walkthroughDo I need to gap the new spark plugs?
No. The recommended iridium spark plugs for your i-290 (like the OEM AC Delco 41-103) come pre-gapped. Attempting to change the gap can damage the fine iridium tip. It's a good practice to gently check the gap with a feeler gauge to ensure it wasn't damaged in shipping, but do not try to adjust it. The correct gap is around 0.040 inches.
Should I replace the ignition coils at the same time?
It is not required, but it can be a good preventative measure, especially if your truck has high mileage. The ignition coils sit directly on top of the spark plugs and must be removed to access them. Replacing them at the same time as the plugs can save you from doing the same labor twice if a coil fails soon after.
Are there any recalls for the spark plugs on my Isuzu i-290?
No, there are no specific recalls or widespread Technical Service Bulletins (TSBs) from Isuzu or GM related to spark plug failure on the 2007-2008 i-290 or its Chevy Colorado counterpart.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12625058 41-103 12598004 12622441
The OEM spark plug is an Iridium type with a 14mm thread, 5/8 inch (16mm) hex size, and a pre-set gap of approximately 0.040-0.043 inches.
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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.
- Isuzu i-290: