A Guide to Replacing Ignition Coils on the 2011-2013 INFINITI M56
Diagnose a misfiring V8 and choose the right aftermarket ignition coil to restore your M56's performance.
- The M56 V8 uses two different ignition coils: one part for cylinders 1-6 and another for the rear cylinders 7 and 8.
- A flashing check engine light signals a severe misfire; pull over immediately to prevent expensive catalytic converter damage.
- Hitachi is the Original Equipment Manufacturer (OEM) for INFINITI, offering dealer quality at a lower price.
- Replacing a single coil is a simple DIY job for most cylinders, requiring only basic tools and less than an hour.
Signs of a Failing Ignition Coil in Your M56
When an ignition coil starts to fail on your M56’s 5.6L V8, the symptoms are usually hard to ignore. Because the coil is essential for firing a cylinder, a bad coil means one of your eight cylinders isn't working correctly. This is known as a misfire.
Common symptoms include:
- Rough Idle: The engine may shake or vibrate noticeably when you're stopped at a light.
- Engine Misfires: You may feel the car jerking, sputtering, or hesitating during acceleration.
- Check Engine Light: A failing coil will trigger the check engine light. If the light is steady, get it checked soon. If it's flashing, it indicates a severe misfire that could damage your catalytic converters. Pull over and shut off the engine as soon as it's safe to do so.
- Loss of Power: With one cylinder not contributing, your M56 will feel sluggish and less powerful.
- Worse Gas Mileage: The engine has to work harder to compensate for the dead cylinder, leading to increased fuel consumption.
Common Ordering Mistake for M56 Ignition Coils
The INFINITI M56 V8 engine uses two different types of ignition coils. Cylinders 1 through 6 use one part number, while the two rearmost cylinders (7 and 8) use a different one. Always verify which cylinder is misfiring before ordering a replacement. Swapping a coil from a known good cylinder to the misfiring one can help confirm the failure. If the misfire code moves to the new cylinder, you've found the bad coil.
🎬 Watch: How to diagnose and repair a specific cylinder misfire.Choosing the Right Aftermarket Ignition Coil
When replacing an ignition coil, you don't have to buy the expensive part from an INFINITI dealer. Many aftermarket brands offer excellent quality, and some are even the original equipment manufacturer (OEM).
Tier 1: OEM Supplier & Premium Aftermarket
These brands are known to be the original equipment supplier or are highly regarded for their quality and reliability in ignition systems. They are the safest bet for a long-lasting repair.
- Hitachi: Hitachi is the original equipment manufacturer for Nissan and INFINITI ignition coils. Choosing a Hitachi coil is like getting the genuine dealer part without the branded box and higher price tag. This is the most recommended option.
- NGK: NGK is a world leader in ignition components, famous for their spark plugs. Their ignition coils are also built to high standards and are an excellent alternative to OEM.
- Delphi: Delphi is a major OE supplier for many car brands and has a strong reputation for quality electronics. They are a reliable choice for your M56.
Tier 2: Reputable Aftermarket Brands
These brands are well-known in the aftermarket and offer a good balance of price and quality. They are a solid choice for most repairs.
- Standard Ignition (Standard Motor Products): A long-standing American company, SMP produces reliable ignition components. Forum users generally have good experiences with their products.
- Denso: While Hitachi is the primary OEM for this application, Denso is another top-tier Japanese OE supplier known for exceptional reliability.
Tier 3: Budget-Friendly Options
Brands like DriveWire, Spectra, Walker Products, and various private labels found online offer significant cost savings, often sold in full sets of eight. While tempting, their long-term durability can be inconsistent. They can be a viable option for a quick fix or if budget is the primary concern, but for peace of mind, sticking with a higher-tier brand is recommended.
Pro Tip: Replace Spark Plugs at the Same Time
If you're replacing an ignition coil, especially on a higher-mileage M56, it's a good idea to replace the spark plug in that same cylinder. An old or fouled spark plug can put extra strain on a new ignition coil, potentially causing it to fail prematurely. If you're replacing all eight coils, you should replace all eight spark plugs.
🎬 See this walkthrough for replacing coils and plugs on the 5.6L.Known Issues, Recalls, and Service Bulletins
While there are no official recalls for ignition coils on the 2011-2013 INFINITI M56, some Technical Service Bulletins (TSBs) on other INFINITI models point to potential related issues. One TSB for older models noted that poor engine grounding could cause ignition coils to fail. Another bulletin highlights that loose ignition coil ground connections at the back of the cylinder heads can cause random misfires on one or both banks of the V8. If you experience recurring coil failures, it's worth having a mechanic inspect the engine's main ground straps.
Cost of Replacing an INFINITI M56 Ignition Coil
| Part/Service | Estimated Cost |
|---|---|
| New OEM Ignition Coil (Dealer) | $130 - $200 (per coil) |
| New Aftermarket Ignition Coil | $35 - $150 (per coil) |
| Shop Labor | $125 - $195 (to replace one coil) |
| Total Professional Replacement | $225 - $293 (with aftermarket part) |
Frequently Asked Questions (FAQ)
Do I need to replace all eight ignition coils at once?
No, you don't have to. Unlike spark plugs, ignition coils are typically replaced only when they fail. However, since they are all the same age, it's not uncommon for another coil to fail soon after the first one. If one fails and your budget allows, replacing them as a full set can save you future labor costs and provide peace of mind.
Is it difficult to replace an M56 ignition coil myself?
For most cylinders, it's a very easy job. The coil is located directly on top of the engine and held in place by a single 10mm bolt. You simply disconnect the electrical connector, undo the bolt, and pull the old coil out. The rear two cylinders (7 and 8) are harder to access and may require removing the engine cover for more room. This is a very DIY-friendly repair for those with basic tools.
🎬 Watch: A DIY guide to fixing P0300 codes on Nissan/Infiniti V8s.What diagnostic code points to a bad ignition coil?
A general misfire code is P0300 (Random/Multiple Cylinder Misfire). More specific codes, like P0301 for cylinder 1, P0302 for cylinder 2, and so on up to P0308 for cylinder 8, will tell you exactly which cylinder is having the problem. This helps you identify which coil to test and replace.
Is Hitachi really the same as the OEM INFINITI part?
Yes. Hitachi is the Original Equipment Manufacturer that supplies ignition coils to INFINITI for the M56. A coil in a Hitachi box is the same part you would get from the dealer, just without the INFINITI branding and associated markup.
Helpful Videos
Technical Specifications
OEM Part Numbers: 22448-EY00A (Cylinders 1-6) 22448-1LA0B (Cylinders 7-8) 22448-JA00C (Superseded)
Coil-on-Plug (COP) design, distributorless ignition. Requires 8 coils total (6 of one type, 2 of another).
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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 M56:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Signs of a Failing Ignition Coil in Your M56
- Common Ordering Mistake for M56 Ignition Coils
- Choosing the Right Aftermarket Ignition Coil
- Tier 1: OEM Supplier & Premium Aftermarket
- Tier 2: Reputable Aftermarket Brands
- Tier 3: Budget-Friendly Options
- Pro Tip: Replace Spark Plugs at the Same Time
- Known Issues, Recalls, and Service Bulletins
- Cost of Replacing an INFINITI M56 Ignition Coil
- Frequently Asked Questions (FAQ)
- 🎟️ Get 5% Off