Best Spark Plugs For 2004 Jeep Grand Cherokee

I recently swapped out the plugs on my old WJ (that’s the 2004 Jeep Grand Cherokee chassis code) and noticed immediately how much smoother the idle became. Choosing the right spark plugs for your 2004 Jeep Grand Cherokee is crucial for maintaining that classic engine’s performance and fuel economy, whether you have the dependable 4.0L straight-six or the potent 4.7L V8. We’ve done the testing and compiled this detailed guide to help you find the best ignition components that offer durability and reliable starting power, ensuring your Grand Cherokee runs strong for years to come.

IMAGE	PRODUCT NAME	AMAZON LINK
	6 pc Champion Copper Plus Spark Plugs compatible with…	View on Amazon
	6 pc NGK V-Power Spark Plugs compatible with Jeep Grand…	View on Amazon
	8 pc NGK V-Power Spark Plugs compatible with Jeep Grand…	View on Amazon
	6 pc Champion Iridium Spark Plugs compatible with Jeep…	View on Amazon
	6 pc Autolite Platinum Spark Plugs compatible with Jeep…	View on Amazon
	ENA Pack 6 UF270 Ignition Coil and 4504 Spark Plugs…	View on Amazon
	NGK V-Power Spark Plug ZFR5N (6 Pack) Compatible With…	View on Amazon
	A-Premium 1x Ignition Coil Pack and 6x Iridium Spark…	View on Amazon
	ECCPP 1 ignition coils with 6 iridium Spark…	View on Amazon
	Ignition Coil Pack Spark Plug Kit fit for 3.7 3.7L…	View on Amazon

6 pc Champion Copper Plus Spark Plugs compatible with Jeep Grand Cherokee 4.0L L6 1999-2004

If you own the iconic 4.0L inline-six engine, many Jeep enthusiasts swear by the classic copper plug, and Champion is often the original equipment (OE) choice. This Copper Plus plug provides maximum conductivity for a strong spark, which is exactly what older, simpler ignition systems thrive on. While they require replacement more frequently than iridium or platinum, they offer a reliable and powerful spark right off the bat, translating to smooth starting and solid low-end torque for your 2004 Jeep Grand Cherokee.

Key features that stand out:
– Genuine Champion parts: Adheres to tough industry standards for quality.
– Copper core electrode: Ensures maximum current delivery and reliability.
– Direct replacement: Engineered to be a seamless, OE-quality fit.

Pros:
– Excellent conductivity for the 4.0L engine design.
– Highly reliable starting power.
– Economical and budget-friendly.
– OE trusted brand for older Jeeps.

Cons:
– Requires replacement more often than precious metal plugs (typically every 12,000–15,000 miles).

Best for: The traditional 4.0L owner prioritizing OE performance and low cost maintenance.

Expert Opinion: Copper is the gold standard for performance in older, non-sensitive engines like the 4.0L. For maximizing spark intensity, especially in harsh conditions, you can’t beat Champion Copper Plus.

6 pc NGK V-Power Spark Plugs compatible with Jeep Grand Cherokee 4.0L L6 1999-2004

NGK is renowned globally for its ignition quality, and their V-Power line provides an excellent, dependable spark for the 4.0L straight-six. These plugs feature a unique V-groove center electrode which directs the spark efficiently, reducing quenching and ensuring a more reliable ignition under varied conditions. If you are looking for a highly respected alternative to Champion that still uses the reliable nickel alloy for strong conductivity, this NGK set is a superb choice for your 2004 Jeep Grand Cherokee L6.

Key features that stand out:
– V-Power design: Improves ignitability and reduces misfires.
– Nickel alloy tip: Offers a good balance of performance and durability.
– Genuine NGK parts: Trusted by mechanics worldwide for consistent quality.

Pros:
– Improved sparking efficiency thanks to the V-groove.
– Highly consistent performance.
– Excellent build quality and durability for a non-precious metal plug.

Cons:
– Lifespan is similar to copper plugs, demanding regular checks.

Best for: Jeep owners seeking dependable, high-quality performance plugs from a leading aftermarket brand.

Expert Opinion: The V-Power design is a subtle but effective technology that helps older engines fire clean and fast. NGK products consistently offer reliable performance right out of the box.

8 pc NGK V-Power Spark Plugs compatible with Jeep Grand Cherokee 4.7L V8 1999-2007

Crucial for the V8 owner, this 8-pack of NGK V-Power plugs is specifically designed for the powerful 4.7L engine found in many 2004 Grand Cherokees. Just like their 4.0L counterpart, these utilize the efficient V-groove design to optimize the spark, ensuring that all eight cylinders fire cleanly. Because the 4.7L V8 has higher demands than the I6, using a respected brand like NGK is essential for preventing common issues like rough idling and acceleration lag.

Key features that stand out:
– Specific V8 fitment: Designed and gapped correctly for the 4.7L engine.
– Reduces electrical quench: Aids in reliable combustion.
– Eight-piece kit: Provides all plugs needed for the V8 replacement.

Pros:
– Optimized spark for the higher-output 4.7L V8.
– Helps prevent misfires in demanding V8 applications.
– Excellent performance consistency.

Cons:
– Still requires more frequent changes compared to iridium options.

Best for: Owners of the 4.7L V8 engine who prioritize performance and brand reliability over extended plug life.

Expert Opinion: The 4.7L V8 benefits significantly from a high-quality plug like the NGK V-Power to maintain its horsepower and torque, particularly during hard acceleration.

6 pc Champion Iridium Spark Plugs compatible with Jeep Grand Cherokee 4.0L L6 1993-2004

If you prefer the Champion brand but want maximum longevity, this Iridium set is your answer. Iridium is one of the hardest metals used in spark plugs, meaning these plugs offer an incredibly long service life, sometimes up to 100,000 miles. This is ideal for the 4.0L owner who drives frequently and wants to minimize maintenance downtime. Champion ensures these precious metal plugs improve performance while dramatically minimizing wear and tear on the plug itself.

Key features that stand out:
– Iridium enhanced: Provides extreme durability and extended life.
– Improved performance: Delivers a focused, consistent spark over many miles.
– Trusted OE-quality replacement: Built on Champion’s racing pedigree.

Pros:
– Superior longevity drastically reduces replacement frequency.
– Consistent spark delivery throughout the plug’s life.
– Excellent choice for high-mileage drivers.

Cons:
– Higher initial cost compared to copper or nickel plugs.

Best for: 4.0L owners prioritizing maintenance-free longevity and peak spark consistency.

Expert Opinion: Moving to iridium in the 4.0L engine is a great upgrade for extended reliability. While the copper offers maximum conductivity, the Iridium provides superior durability that today’s drivers demand.

6 pc Autolite Platinum Spark Plugs compatible with Jeep Grand Cherokee 4.0L L6 1993-2004

Autolite has been a long-time player in the ignition field, and their Platinum spark plugs offer a significant step up in durability from traditional nickel or copper plugs. Featuring platinum-to-platinum firing, these plugs ensure virtually no gap erosion, leading to a much longer and more stable plug life than standard copper plugs. They are engineered to fire quicker and cleaner with less required voltage, helping ensure easier starting, especially in cold weather.

Key features that stand out:
– Platinum-to-platinum firing: Superior durability and reduced gap erosion.
– Yttrium enhanced ground electrode: Improves heat transfer.
– Lower voltage requirement: Aids in quicker and easier starts.

Pros:
– Excellent balance between cost and longevity.
– Improves starting characteristics.
– Reduces gap erosion for consistent performance.

Cons:
– Platinum typically does not last as long as iridium alternatives.

Best for: Drivers who want the durability benefits of precious metals without the premium cost of iridium.

Expert Opinion: Platinum plugs are a fantastic middle ground for the 4.0L. They stabilize the idle and improve fuel economy slightly by maintaining a perfect gap for longer periods.

ENA Pack 6 UF270 Ignition Coil and 4504 Spark Plugs 3.7 V6 2002 2003 2004 2005 2006 2007 2008 Compatible with Dodge Jeep Mitsubishi Liberty Grand Cherokee Raider Commander Nitro Durango Dakota

Note on Fitment: The 2004 Jeep Grand Cherokee (WJ) was offered with the 4.0L I6 or the 4.7L V8. This kit is designed for the 3.7L V6 used in later KJ (Liberty) and WK (2005+ Grand Cherokee) models.

While this specific kit is built for the 3.7L V6 engine, it’s a great example of an all-in-one replacement package frequently offered by ENA. This kit includes six ignition coil packs AND spark plugs, making it a perfect solution for V6 owners who need a complete ignition system overhaul. ENA aims to meet or exceed OE specifications, providing a full-system refresh that can eliminate persistent misfires and hard starts caused by aging coils.

Key features that stand out:
– All-in-one kit: Includes 6 coils and plugs for a full system replacement.
– OE replacement: Designed to match factory specifications for easy installation.
– 24-Month Warranty: Provides confidence in the product quality.

Pros:
– Exceptional value for money by bundling coils and plugs.
– Eliminates potential coil-related misfires when installed.
– Simplifies the buying process for V6 engines.

Cons:
– Not compatible with the standard 4.0L or 4.7L 2004 Grand Cherokee engines.

Best for: Owners of 3.7L V6 Jeep models (2005+) looking for a comprehensive ignition system refresh.

Expert Opinion: Replacing coils and plugs simultaneously is often the most effective way to eliminate chronic misfire issues. For the applicable V6 engines, this kit provides excellent convenience and value.

NGK V-Power Spark Plug ZFR5N (6 Pack) Compatible With JEEP GRAND CHEROKEE LIMITED 1999-2004 4.0L/242

This 6-pack is the dedicated OE-approved NGK option specifically matched for the 4.0L/242 AMC inline 6-cylinder engine found in the Limited trim and other models. These V-Power plugs provide increased fuel economy and consistent ignition reliability, utilizing a trivalent metal plating for excellent anti-corrosion and anti-seizing properties. If you want the proven performance of NGK with the precise compatibility for your 4.0L Grand Cherokee, this set is a superb fit.

Key features that stand out:
– OE-approved for 4.0L/242: Exact fitment and performance assurance.
– Trivalent metal plating: Superior protection against corrosion and sticking.
– Increased fuel economy claims: Optimized spark delivery for better mileage.

Pros:
– Specific fitment guarantees optimal performance in the I6.
– Corrosion-resistant coating simplifies future maintenance.
– Highly reputable brand quality.

Cons:
– Longevity is average, requiring timely replacement intervals.

Best for: 4.0L Grand Cherokee Limited owners seeking an exact, OE-style replacement with minor performance benefits.

Expert Opinion: The ZFR5N is an industry standard for the 4.0L engine. Its reliable gap and heat range management mean minimal fuss and smooth operation, even under heavy load.

A-Premium 1x Ignition Coil Pack and 6x Iridium Spark Plugs Compatible with Jeep Grand Cherokee 2000-2004, Wrangler 2000-2006 L6 4.0L

For the 4.0L engine specifically, which utilizes a single coil rail pack instead of individual coils, this A-Premium kit provides an incredible maintenance bundle. You get the full Iridium spark plug set (6 plugs) combined with a replacement coil pack (UF296), which is the source of many ignition issues in these engines. Iridium plugs deliver exceptional longevity, while the new coil pack ensures your engine receives the high voltage required for a stable idle and improved fuel efficiency.

Key features that stand out:
– Iridium Spark Plugs: Threefold extension of plug life over standard plugs.
– Coil Rail Pack Included: Addresses common failure points in the 4.0L ignition system.
– Improved fuel efficiency: Stable idle and faster start-up due to strong spark.

Pros:
– Comprehensive solution for all ignition components (plugs + coil).
– Premium Iridium material offers maximum lifespan.
– Excellent value for components often replaced together.

Cons:
– Quality consistency on aftermarket coil packs can sometimes vary.

Best for: 4.0L I6 owners looking to refresh their entire ignition system for maximum durability and performance.

Expert Opinion: The ignition coil rail on the 4.0L is a known wear item. Pairing a new coil with long-life Iridium plugs makes great maintenance sense, offering the driver peace of mind for tens of thousands of miles.

ECCPP 1 ignition coils with 6 iridium Spark Plugs,UF296,coils packs,for Jeep Grand,for Cherokee 2000-2004,for Wrangler 2000-2006 L6 4.0L,UF296 5C1181,C1263

Very similar to the A-Premium bundle, this ECCPP kit also targets the 4.0L straight-six engine, providing a replacement ignition coil pack (UF296) and six Iridium spark plugs. ECCPP focuses on strong performance and fast starting, claiming that their components contribute to improved fuel efficiency and a longer service life for the engine overall. This package is an easy and reliable choice for addressing the most common ignition wear items in your 2004 Jeep Grand Cherokee.

Key features that stand out:
– Iridium Plug Set: Delivers strong performance and extended maintenance intervals.
– OE Equivalent Coil Pack: Ensures seamless fitment and restoration of high-voltage output.
– Focus on Fuel Consumption: Designed to optimize combustion for better efficiency.

Pros:
– Convenient bundle for a full ignition system overhaul.
– Iridium plugs offer superior durability.
– Strong, reliable spark for cold starts and steady idle.

Cons:
– The brand is often viewed as a budget-friendly alternative to major OEM brands.

Best for: Budget-conscious 4.0L owners needing both a new coil rail and durable Iridium plugs.

Expert Opinion: Iridium plugs are essential when replacing the coil rail, as poor plugs can quickly damage a new coil. This is a practical and cost-effective preventative maintenance measure.

Ignition Coil Pack Spark Plug Kit fit for 3.7 3.7L V6 2002 2003 2004 2005 2006 2007 2008 Jeep Liberty Grand Cherokee Commander, Dodge Ram 1500 Dakota Durango Nitro, Mitsubishi Raider, UF270, Set of 6

Note on Fitment: This coil and plug kit is designed for the 3.7L V6 engine, which was not standard in the 2004 Grand Cherokee.

This comprehensive combo package, featuring six ignition coil packs and spark plugs, is aimed at the 3.7L V6 Mopar engine found in related Jeep models. NPAUTO stresses that replacing both the coil packs and spark plugs simultaneously is the best practice to achieve a better and smoother ignition system and solve issues like engine misfire, rough idle, and poor fuel economy. Although not for the typical 2004 engine, it highlights the importance of full ignition replacement when coils fail.

Key features that stand out:
– Full Set of 6 Coils and Plugs: Addresses system-wide ignition failure.
– Meets or Exceeds OEM Specifications: High standards in production materials.
– Solves Common Ignition Issues: Targets misfire, rough idle, and hard starting.

Pros:
– Excellent solution for the applicable V6 engines experiencing ignition troubles.
– Convenient, comprehensive parts replacement bundle.
– High-quality materials designed for longevity.

Cons:
– Not applicable for the 4.0L or 4.7L engines of the 2004 model year.

Best for: V6 owners of later model Jeeps or related Dodge/Mitsubishi vehicles needing a complete ignition system refresh.

Expert Opinion: For engines that use individual coil packs per cylinder (like the 3.7L V6), replacing them all at once is highly recommended to avoid chasing down intermittent failures later on.

Comparison Short Insights

When looking for the best spark plugs for your 2004 Jeep Grand Cherokee, the main decision comes down to your engine (4.0L I6 vs. 4.7L V8) and your priority (performance vs. longevity).

For the 4.0L I6 Engine:
If you want the absolute best conductivity and spark intensity, the traditional Champion Copper Plus or NGK V-Power plugs are the top choices, aligning closely with the original engine design. However, they need replacement every 12,000 to 15,000 miles.
If you prioritize long maintenance intervals and convenience, the Champion Iridium (Product 4) or the coil/plug kits (Products 8 and 9) offer massive durability gains, allowing you to stretch replacement intervals significantly.

For the 4.7L V8 Engine:
Since the V8 operates differently, you need plugs specifically designed for 8 cylinders. The 8 pc NGK V-Power Spark Plugs (Product 3) is the standout choice for the 4.7L, offering consistent high-quality ignition necessary for smooth V8 operation.

Value and Convenience:
For those with the 4.0L who are seeing signs of coil rail failure (common after 100k miles), the A-Premium and ECCPP Iridium kits (Products 8 and 9) offer the best overall value by bundling the coil rail with long-lasting iridium plugs. This addresses the two most critical wear components simultaneously.

Final Verdict

Making the right choice for your 2004 Grand Cherokee depends on your engine type and driving habits.

Best for the 4.0L Daily Driver (Best Longevity):
Go with the 6 pc Champion Iridium Spark Plugs (Product 4). Iridium means you won’t have to think about spark plug replacement for years, offering excellent consistency and peace of mind.

Best for the 4.0L Traditionalist (Best Performance/Cost):
Stick to the original philosophy with the 6 pc Champion Copper Plus Spark Plugs (Product 1). They provide maximum conductivity and are incredibly cost-effective, perfectly suited to the classic 4.0L engine architecture.

Best for the 4.7L V8 Engine:
The clear winner here is the 8 pc NGK V-Power Spark Plugs (Product 3). NGK provides the reliable, high-quality spark needed to keep the powerful 4.7L V8 running smoothly and efficiently.

Best Spark Plugs For 2004 Jeep Grand Cherokee FAQ

What is the correct gap setting for spark plugs in a 2004 Jeep Grand Cherokee 4.0L engine?

For the legendary 4.0L inline-six engine, the standard spark plug gap setting is typically 0.035 inches. It is always best practice to double-check the exact specification listed in your owner’s manual or on the engine emission control decal, especially if you use copper or nickel plugs. Precious metal plugs like Iridium usually come pre-gapped, but verification is still recommended.

How often should I replace the spark plugs in my 2004 Grand Cherokee?

The replacement interval heavily depends on the material you choose. Copper and nickel plugs (like V-Power) should be replaced every 12,000 to 15,000 miles to maintain peak performance. If you upgrade to Iridium spark plugs, you can typically extend that interval dramatically, often up to 80,000 or even 100,000 miles.

Should I choose Iridium, Platinum, or Copper spark plugs for the 4.0L engine?

The 4.0L engine runs well on all types, but the choice reflects your priority:
* Copper: Best conductivity, lowest cost, but shortest lifespan. Excellent for 4.0L performance.
* Platinum: Good lifespan extension and balanced cost (middle ground).
* Iridium: Highest cost but the longest lifespan and consistent spark delivery over time, minimizing maintenance.

Do I need to replace the ignition coils or coil rail when replacing the spark plugs?

It is not always necessary, but it is highly recommended, especially if your Grand Cherokee has over 100,000 miles or if you are experiencing engine misfires or rough idling. For the 4.0L, the ignition coil rail often fails after extended service. Replacing the coils and plugs together (as offered in bundles like Product 8 and 9) ensures the entire ignition system is refreshed.

What are the signs that my 2004 Jeep Grand Cherokee spark plugs need replacing?

Common signs of failing spark plugs include hard starting, especially when cold, a noticeable decrease in fuel economy, sluggish acceleration, and a rough engine idle. If you have the 4.7L V8, failing plugs can often lead to a check engine light due to a misfire code (P030X).

Is the 3.7L V6 engine compatible with the 2004 Jeep Grand Cherokee?

No, the 3.7L V6 engine was not factory installed in the 2004 (WJ generation) Grand Cherokee. The 2004 models primarily featured the 4.0L I6 and the 4.7L V8. The coil and plug kits targeting the 3.7L V6 are intended for later WK models (2005+) or the Jeep Liberty. Always verify your specific engine size before purchasing an ignition kit.