A Guide to Ignition Coils for the 2005-2010 Buick Allure
If your Allure is shaking, misfiring, or has a check engine light, a bad ignition coil is a likely cause.
- First, identify your engine (3.8L V6, 3.6L V6, or 5.3L V8) to determine if you need a coil-on-plug or a coil from a coil pack.
- A flashing check engine light is a critical warning to stop driving to prevent expensive damage to the catalytic converter.
- On 3.8L V6 engines, the Ignition Control Module (ICM) can fail independently of the coils and cause a no-spark issue.
- For 3.6L and 5.3L engines, the 'swap test' is a simple and effective way to confirm a specific coil has failed.
Is it a Coil Pack or Coil-on-Plug?
Before buying a new ignition coil, you must know which engine your Buick Allure has. This determines the type of ignition system and the parts you need.
- 3.6L V6 & 5.3L V8 Engines: These models use a modern Coil-on-Plug (COP) system. Each spark plug has its own individual coil sitting directly on top of it. This makes diagnosis simple, as you can isolate the problem to a single coil.
- 3.8L V6 Engine: This engine uses a Distributorless Ignition System (DIS) that features a single coil pack mounted to an Ignition Control Module (ICM). This assembly contains three coils. Each coil provides spark for two cylinders in what is called a "waste spark" system. A failure in this system can be a bad coil or a bad ICM.
Symptoms of a Failing Ignition Coil
When a coil starts to fail, the signs are hard to miss. Your car's computer will almost always turn on the Check Engine Light.
- Check Engine Light: This is usually the first warning. If the light is steady, get it checked soon. If it's flashing, it signals a severe misfire. 🎬 Watch: Diagnosing an intermittent P0300 misfire code on a Buick. You should pull over and stop driving as soon as it is safe to do so. A flashing light means unburned fuel is entering the exhaust, which can quickly destroy your expensive catalytic converter.
- Engine Misfire or Stumble: The most common symptom is a feeling of shaking, sputtering, or stumbling from the engine. This is most noticeable when idling or accelerating.
- Rough Idle: Your Allure may shake or vibrate more than usual when you're stopped at a traffic light.
- Loss of Power: With one or more cylinders not firing correctly, your car will feel sluggish and weak when you try to accelerate.
- Worse Fuel Economy: The engine has to work harder to compensate for the misfire, causing it to burn more gasoline.
- Smell of Gas: A failing coil can prevent fuel from being burned in the cylinder. This raw fuel then travels out the exhaust, creating a strong gasoline smell.
Choosing the Right Aftermarket Ignition Coil
With many brands available, choosing the right one can be confusing. For a critical part like an ignition coil, quality matters. A General Motors bulletin noted that some non-OEM (aftermarket) ignition coils on the 3.8L engine have caused crank-no-start issues. Sticking with reputable brands is a safe bet.
Brand Quality Tiers
Premium (OEM-Equivalent): Brands like ACDelco (the original GM part), Delphi, NGK, and Denso are known for their reliability and are often recommended on owner forums. Standard Motor Products (SMP) is also a well-respected premium option.
Reputable Aftermarket: Brands such as Hitachi and Walker Products often provide good quality at a lower price point than premium brands.
Economy: While budget-friendly, be aware that the lowest-priced coils may have a shorter lifespan. Given the potential for issues noted by GM, it's often worth spending a little more for a part from a well-known manufacturer.
How Much Does an Ignition Coil Cost?
The cost depends on your engine and the brand you choose. You can replace just the one failed coil or the full set.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Coil (Single) | $25 - $90 |
| New OEM Coil (Single) | $50 - $120 |
| New Aftermarket Coil Set (V6/V8) | $120 - $450+ |
| Shop Labor for Diagnosis & Replacement | $95 - $150 |
Frequently Asked Questions (FAQ)
Should I replace all the ignition coils at once?
It is a good preventative measure. Ignition coils are subjected to the same heat and wear, so if one has failed, others may soon follow. For engines where access is difficult (not typically the case for the Allure), replacing them all at once saves on future labor costs. For the Allure's easily accessible coils, replacing only the failed one is a reasonable option if you are on a budget.
What is an Ignition Control Module (ICM) and does my car have one?
Only the 3.8L V6 engine has an Ignition Control Module (ICM). It is the electronic part that the three ignition coils bolt onto. The ICM's job is to receive signals from the engine computer and tell the coils when to fire. Sometimes the ICM can fail, causing a no-spark condition even with good coils. If you replace a coil on the 3.8L and the problem doesn't go away, the ICM is the next part to test.
🎬 Watch: Troubleshooting the 3.8L ignition module and coil firing order.Was there an ignition recall for my 2005-2010 Buick Allure?
Yes, but it was for the ignition switch and key, not the ignition coils. This recall (affecting the 2005-2009 LaCrosse/Allure) addressed a defect where the key could accidentally turn out of the 'run' position while driving, shutting off the engine and disabling airbags. This is a separate issue from an engine misfire caused by a bad coil.
How do I find out which coil is bad?
First, use an OBD-II scanner to read the trouble code, which will point to a specific cylinder (e.g., P0304 for cylinder 4). For 3.6L or 5.3L engines, the easiest way to confirm is the 'swap test'. Mark and swap the suspected bad coil with a known good coil from another cylinder. Clear the codes and run the engine. If the misfire code moves to the new cylinder, you've confirmed the coil is faulty. For the 3.8L engine, you can test the coil's resistance with a multimeter or swap its position with another coil on the module to see if the misfire changes cylinders.
Helpful Videos
Technical Specifications
OEM Part Numbers: DR39 10467067 10472401 D555 UF375 C1508
System Type: Coil-on-Plug (3.6L V6, 5.3L V8) or Coil Pack (3.8L V6). Voltage: Transforms 12V to over 25,000V. One coil per cylinder for COP systems; three coils total for 3.8L coil pack.
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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.
- Buick Allure: