Infiniti G35 Ignition Coil Guide for 2003-2008 Models
Everything G35 owners need to know about replacing faulty ignition coils to restore engine performance.
- Hitachi is the original OEM supplier; choosing this brand ensures OEM quality.
- Before replacing coils, check for oil in the spark plug wells from a leaking valve cover gasket, a very common G35 issue.
- Replacing all six coils at once on a high-mileage G35 is recommended to prevent future failures.
- Ensure you buy the correct coils; 2007-2008 sedans with the VQ35HR engine use different coils than the VQ35DE models.
Is Your G35 Running Rough? It Could Be an Ignition Coil.
A failing ignition coil is a common issue for the 2003-2008 Infiniti G35. When a coil goes bad, it can't deliver the high voltage spark your engine needs. This often leads to noticeable problems like a rough idle, engine hesitation, a loss of power, and a drop in fuel economy. You will almost always see the 'Service Engine Soon' light appear on your dashboard.
A Common Related Problem: Leaking Valve Cover Gaskets
Before you replace your ignition coils, it's critical to check the spark plug wells for oil. The valve cover gaskets on the VQ35DE engine are known to fail, allowing oil to leak down into the spark plug tubes. This oil can damage the ignition coil boot and cause the coil itself to fail prematurely. If you find oil, you must replace the valve cover or gaskets 🎬 Watch this step-by-step guide to replacing your valve cover gaskets. before installing new coils, or the new parts will likely fail again.
Symptoms of a Bad Ignition Coil
If your G35 has a bad ignition coil, you'll likely experience one or more of the following symptoms:
- Engine Misfires: The engine may shake, stumble, or hesitate, especially during acceleration.
- Rough Idle: Your car may vibrate or run unevenly when stopped.
- Check Engine Light: A failing coil will trigger a Diagnostic Trouble Code (DTC), illuminating the check engine light. Common codes include P0300 (Random Misfire) or P0301-P0306 (for specific cylinders).
- Reduced Fuel Economy: An inefficient spark means wasted fuel.
- Loss of Power: Your G35 will feel noticeably slower and less responsive.
Choosing the Right Aftermarket Ignition Coil
You don't need to buy the most expensive ignition coil, but you should be careful with the cheapest options. For the G35, quality aftermarket brands offer a great balance of price and performance.
Hitachi is the Original Equipment Manufacturer (OEM) for the Infiniti G35. This means they made the original parts for Infiniti. Choosing Hitachi aftermarket coils is the closest you can get to the original part without the dealership price tag.
Brand Quality Tiers
- OEM / Premium Aftermarket: Hitachi, NGK, and Delphi are top-tier choices known for reliability and performance that meets or exceeds original standards. These are highly recommended for G35 owners.
- Quality Mid-Range: Brands like Standard Ignition (SMP) and Walker Products offer a solid balance of quality and value. They are generally reliable and a good step up from budget parts.
- Budget-Friendly: Brands like DriveWire, Skyward, and others can be very affordable. While they may work, their long-term durability can be a gamble. They might be a choice if budget is the primary concern, but be aware you may be replacing them sooner.
Pro Tip: Engine Differences Matter
The 2003-2007 G35 Coupe and 2003-2006 G35 Sedan use the VQ35DE engine. The 2007-2008 G35 Sedan uses the newer VQ35HR engine. These engines use different ignition coils. Always verify the exact fitment for your specific year, model, and engine type before ordering.
Cost to Replace Infiniti G35 Ignition Coils
| Part Type | Cost per Coil | Cost for Set of 6 |
|---|---|---|
| New OEM (Dealer) | $125 - $200 | $750 - $1200 |
| New Aftermarket (Premium) | $50 - $110 | $300 - $660 |
| New Aftermarket (Budget) | $33 - $50 | $198 - $300 |
| Shop Labor (Set of 6) | $120 - $250 | |
Frequently Asked Questions
Do I have to replace all six ignition coils at once?
While you can replace just the one faulty coil, it's often recommended to replace all six at the same time, especially if your car has high mileage (over 80,000 miles). Coils are wear-and-tear items, and if one has failed, others may be close behind. Replacing them all at once saves you from repeated repairs down the road.
What is a P030X code?
This is the Diagnostic Trouble Code (DTC) for an engine misfire. 'P0300' means a random, multiple-cylinder misfire. Codes 'P0301' through 'P0306' point to a specific cylinder 🎬 See how to diagnose and fix specific cylinder misfire codes. that is misfiring (e.g., P0301 is cylinder 1, P0302 is cylinder 2, etc.). This helps you identify which coil might be failing.
Are there any recalls for G35 ignition coils?
There are no specific recalls for ignition coils on the 2003-2008 Infiniti G35. However, an Infiniti Technical Service Bulletin (ITB11-017a) addresses issues of blistered or melted ignition coils caused by a bad ground, which can lead to misfires. This involves cleaning engine grounds and replacing negative battery cables to ensure the problem doesn't reoccur.
Can I install ignition coils myself?
Yes, for many DIY mechanics, this is a very feasible job. The ignition coils on the G35 are located on top of the engine and are accessible after removing the engine cover and some minor components. The difficulty is low, requiring basic hand tools like a 10mm socket. 🎬 Follow this video walkthrough to replace your ignition coils yourself. A pro-tip is to apply a small amount of dielectric grease to the inside of the new coil boot to ensure a good seal and make future removal easier.
Helpful Videos
Technical Specifications
OEM Part Numbers: 22448-AL61C 22448-AL615 22448-JA10C 22448-EY00A
Coil-on-plug design. One coil required per cylinder. VQ35DE and VQ35HR engines use different part numbers.
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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.
- INFINITI G35:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your G35 Running Rough? It Could Be an Ignition Coil.
- A Common Related Problem: Leaking Valve Cover Gaskets
- Symptoms of a Bad Ignition Coil
- Choosing the Right Aftermarket Ignition Coil
- Brand Quality Tiers
- Pro Tip: Engine Differences Matter
- Cost to Replace Infiniti G35 Ignition Coils
- Frequently Asked Questions
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