A Guide to Ignition Coil Replacement for the 2012-2019 Rolls-Royce Phantom
Keep your V12 engine running smoothly by understanding ignition coil failure and choosing the right replacement part.
- Before replacing coils for multiple misfires, inspect the PCV valves; they are a common and cheaper failure point that causes identical symptoms.
- Use OEM (Bosch) or a top-tier OEM-equivalent (NGK) brand for reliability; the labor cost is too high to risk using budget parts.
- Due to the extensive labor, always replace all 12 ignition coils and all 12 spark plugs at the same time.
- This is a complex job not recommended for DIY; seek a professional with Rolls-Royce or BMW V12 experience.
Understanding Ignition Coil Failure in Your Phantom
Ignition coils are robust components, but they operate in a high-heat, high-voltage environment. Over time, factors like engine heat, vibration, and age can cause them to fail. When a coil starts to fail on your Phantom's N73 V12 engine, it can disrupt the smooth sequence of combustion, leading to noticeable performance issues. It's a wear item that will eventually need replacement, with many mechanics recommending inspection or replacement after 50,000 miles, especially on high-performance engines.
A Critical Note on Misfires: Check the PCV Valves First!
A very common issue on the BMW N73 engine in the Phantom is the failure of the PCV (Positive Crankcase Ventilation) valves. A broken PCV valve can allow unmetered air and oil into the intake, causing widespread, multiple-cylinder misfires. These symptoms are almost identical to ignition coil failure and are often misdiagnosed. Many owners have spent thousands replacing all 12 coils and spark plugs only to find the problem was a pair of inexpensive PCV valves. If you experience a rough idle and misfire codes (P0300, P0301-P0312), it is highly recommended to inspect or replace the PCV valves before replacing the ignition coils.
🎬 Watch this guide on how to fix a rough idle.Symptoms of a Bad Ignition Coil
A failing ignition coil will almost always let you know there's a problem. Here are the most common signs:
- Check Engine Light: This is often the first sign. The light will illuminate or flash if the engine's computer detects a misfire.
- Engine Misfire: You may feel the engine stutter, hesitate, or shake, especially during acceleration or when idling.
- Rough Idle: The engine may sound and feel rough or uneven when the car is stopped.
- Reduced Power and Acceleration: With one or more cylinders not firing correctly, your Phantom will feel noticeably less powerful. 🎬 See how a technician diagnoses a real-world V12 misfire.
- Hard Starting: The engine may take longer than usual to start, or it may crank without starting.
Choosing the Right Aftermarket Ignition Coil
Since your Phantom's V12 engine is a BMW design, you have access to a good range of parts. However, quality is critical for performance and reliability. Cheaper parts have a higher failure rate, and the labor to replace a coil on this engine is significant.
Tier 1: OEM & OEM-Equivalent Brands
This is the safest and most recommended choice for a vehicle like the Phantom. These brands either make the original part for Rolls-Royce/BMW or produce parts to the same exact standard.
- Bosch: Bosch is the original equipment manufacturer (OEM) for the ignition coils used in the Phantom. Choosing Bosch ensures you are getting the exact same quality, fit, and performance as the part that was installed at the factory. For this vehicle, it is the most trusted option.
- NGK: NGK is a highly respected brand known for its quality ignition components. While not the original supplier for this specific coil, they are an OEM for many other manufacturers and produce high-quality performance coils. They are considered a top-tier alternative to Bosch.
Tier 2: Reputable Aftermarket Brands
These brands are well-known in the aftermarket but may have more variable quality control than OEM suppliers. They can be a good option if the OEM parts are unavailable.
- Standard Ignition (Standard Motor Products): SMP is a long-standing aftermarket manufacturer. Their quality can be inconsistent for European vehicles, with some parts being high-quality re-boxed OEM parts and others being lower-quality sourced parts. If considering this brand, try to ensure it is not from their lower-tier "T-series" line.
Tier 3: Budget Brands
These brands compete primarily on price. Given the complexity and labor costs associated with your Phantom, using budget-tier ignition parts is not recommended. Reports of premature failure are more common with these brands.
- Holstein, Spectra, True Tech: While these brands offer a low-cost alternative, their long-term reliability in a high-performance V12 engine is not well-documented. A single coil failure can lead to another expensive repair job. The risk of early failure often outweighs the initial cost savings.
Pro Tip: Replace in Sets
Ignition coils are subjected to the same conditions. If one has failed due to age and heat, others are likely to fail soon. Because accessing the coils on the Phantom's V12 is labor-intensive, it is highly recommended to replace all 12 coils at the same time, along with the spark plugs. This prevents you from having to repeat the same costly repair a few months later.
Estimated Costs for Ignition Coil Replacement
| Item | Estimated Cost |
|---|---|
| OEM Ignition Coil (Single) | $60 - $100+ |
| Aftermarket Ignition Coil (Single) | $35 - $75 |
| Shop Labor | $800 - $1,500+ |
| Total Professional Replacement (All 12) | $1,500 - $3,000+ |
Frequently Asked Questions
Can I drive my Phantom with a bad ignition coil?
It is not recommended. While the car may still run, the engine misfire will cause poor performance, very high emissions, and terrible fuel economy. Most importantly, unburnt fuel can be dumped into the exhaust, where it can overheat and permanently damage the expensive catalytic converters, turning a relatively straightforward repair into a much more costly one.
Should I replace the spark plugs at the same time?
Yes, absolutely. The spark plugs are located underneath the ignition coils, so the labor to access them is the same. Worn spark plugs can also strain the ignition coils, potentially causing them to fail sooner. Replacing them together is standard practice and cost-effective.
Is this a DIY job?
For most owners, this is not a recommended DIY project. The job requires extensive disassembly of components on top of the engine, and the driver's side is particularly challenging. There is a high risk of breaking brittle plastic hoses and connectors. Given the value of the vehicle, this job is best left to a professional mechanic 🎬 Watch a professional service the spark plugs and coils. with experience on BMW and Rolls-Royce V12 engines.
Why are there misfires if my coils are good?
On the Phantom's N73 V12 engine, the most common cause of multiple cylinder misfires is actually failed PCV diaphragm valves, not the ignition coils. These inexpensive parts are often overlooked. Always have the PCV system checked before committing to a full ignition coil replacement.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12137594938 12131712219 12135A06753
Engine Platform: BMW N73. Quantity Required: 12. Type: Coil-on-Plug (COP), Direct Ignition.
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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.
- Rolls-Royce Phantom:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Understanding Ignition Coil Failure in Your Phantom
- A Critical Note on Misfires: Check the PCV Valves First!
- Symptoms of a Bad Ignition Coil
- Choosing the Right Aftermarket Ignition Coil
- Tier 1: OEM & OEM-Equivalent Brands
- Tier 2: Reputable Aftermarket Brands
- Tier 3: Budget Brands
- Pro Tip: Replace in Sets
- Estimated Costs for Ignition Coil Replacement
- Frequently Asked Questions
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