Acura RL Alternator Guide (2005-2012): Choosing the Right Replacement
If your 2005-2012 Acura RL is showing signs of electrical problems, the alternator could be the culprit.
- The original alternator is a Denso; choosing a Denso or Bosch aftermarket unit offers the highest quality and reliability for your RL.
- Symptoms often include a dashboard warning light, dimming headlights, and a whining noise that changes pitch with engine speed.
- While a DIY replacement is possible and takes about 2 hours, it requires removing the serpentine belt and may require removing a cooling fan for access.
- There are no recalls for this part, but watch for power steering fluid leaks from above, as this can cause premature alternator failure.
Is Your Acura RL Alternator Failing?
Alternator failure on the 2005-2012 Acura RL isn't uncommon as the vehicle ages, with many owners reporting issues around or after 100,000 miles. The symptoms often start subtly but can quickly lead to a car that won't start. Paying attention to the early warnings can save you from being stranded.
Common Symptoms of a Bad Alternator
A failing alternator in your RL will cause a variety of electrical issues. Here’s what to look for:
🎬 Watch: A visual guide to identifying bad alternator symptoms.- Warning Lights: The most direct sign is the red battery light on your dashboard. You might also see other warnings like "Check Charging System" or even seemingly unrelated messages like "Check SH-AWD System" as electrical modules lose power.
- Dimming or Flickering Lights: Headlights and interior lights may dim, flicker, or pulse, especially when the engine is at idle. They might get brighter as you press the gas pedal.
- Whining or Grinding Noises: A high-pitched whining noise that changes with engine RPM is a classic sign of failing alternator bearings.
- Slow or Malfunctioning Accessories: You may notice power windows rolling up slowly, the radio cutting out, or other electronics acting strangely.
- Dead Battery: The alternator's job is to charge the battery. If your car needs frequent jump-starts, the alternator is a likely suspect, not just the battery itself.
Known Issue: Power Steering Fluid Leaks
Some Acura and Honda models can develop leaks from power steering components located above the alternator. Leaking fluid can drip onto and into the alternator, contaminating its internal parts and causing premature failure. When replacing your alternator, inspect the power steering hoses and pump for any signs of leaks.
Choosing the Right Aftermarket Alternator
The original alternator in your Acura RL was made by Denso. When choosing a replacement, you have several options that range in quality and price. Aftermarket parts can be a great value, but quality varies significantly between brands.
Tier 1: Premium Aftermarket (Highest Quality)
- Denso: As the Original Equipment Manufacturer (OEM), a new or remanufactured Denso alternator is the closest you can get to the factory part. They are known for reliability and longevity, making them a top choice for Honda and Acura vehicles.
- Bosch: A major OEM supplier for many brands, Bosch offers high-quality new and remanufactured alternators that are considered equivalent to Denso in performance and durability.
Tier 2: Quality Aftermarket (Good Value)
- ACDelco (Gold/Professional): While traditionally a GM brand, their Gold (formerly Professional) line offers quality new and remanufactured parts for many makes, including Acura. They are generally considered a reliable option, though some users report issues with units made in China.
- MPA (Motorcar Parts of America): MPA is a large manufacturer that produces new and remanufactured alternators under brands like Quality-Built and Pure Energy. They aim to meet or exceed OE specs and are a solid mid-range choice.
Tier 3: Economy Brands (Budget-Focused)
- Remy: Now owned by BBB Industries, Remy has a mixed reputation. While some have good experiences, others report premature failures, particularly with bearings, sometimes within a year.
- BBB Industries: This company is one of the largest remanufacturers, supplying many store brands. Quality can be inconsistent; it's a budget option where you might get a good part or one that fails early.
New vs. Remanufactured
A new alternator is made with all-new components. A remanufactured unit has been completely disassembled, cleaned, and had all wear items (like bearings and brushes) replaced with new parts before being tested to meet original specifications. A high-quality remanufactured unit from a top brand like Denso or Bosch can be just as reliable as a new one and offer significant savings. Be cautious with lower-quality remanufactured parts, which have higher failure rates.
How Much Does an Acura RL Alternator Replacement Cost?
The total cost depends on whether you do it yourself or hire a professional. The alternator itself is located at the front of the engine but can be tight to access.
🎬 See this step-by-step walkthrough for replacing the RL alternator.| Cost Type | Estimated Price |
|---|---|
| New Aftermarket Part | $71.77 - $481.05 |
| Shop Labor | $160 - $235 |
| Total Professional Replacement | $230 - $715+ (Aftermarket) |
| New OEM Part (Dealer) | $550 - $790+ |
Note: Prices are estimates and can vary based on your location, the specific brand chosen, and the repair shop's labor rates.
Frequently Asked Questions (FAQ)
Can I drive my RL with a bad alternator?
It is not recommended. Once the alternator fails, your car runs entirely on battery power. Depending on the battery's condition, you may only have a few minutes to a short drive before the car shuts down completely, potentially in an unsafe location.
Is replacing the alternator a DIY job?
For a moderately experienced DIY mechanic, it is feasible. The job requires removing the serpentine belt, disconnecting the battery, removing the radiator overflow tank, and potentially the passenger-side cooling fan for clearance. It takes about 1.5 to 2.5 hours. You will need a serpentine belt tool to release the belt tensioner.
🎬 Watch this video for a detailed DIY replacement guide.Are there any recalls on the 2005-2012 RL alternator?
No, there are no specific recalls issued by the NHTSA for alternator failure on the 2005-2012 Acura RL. However, Acura did issue a Technical Service Bulletin (TSB 12-001) regarding updated procedures for testing alternators with specific diagnostic tools.
Should I replace the serpentine belt and battery at the same time?
It's a great idea. The serpentine belt must be removed for the job, so replacing it at the same time costs nothing extra in labor. A deeply discharged battery can be damaged and may struggle to hold a charge, putting extra strain on your new alternator. It's wise to have your battery tested and replace it if it's old or weak.
Helpful Videos
Technical Specifications
OEM Part Numbers: 31100-RJA-A02 31100-RJA-A01 31100-RDJ-A01 31100-RGL-A01 06311-RJA-505RM 31100-RGW-A01 06311-RGW-505RM
The standard alternator for the 2005-2012 Acura RL is a 130 Amp unit with a 6-groove serpentine pulley and an internal voltage regulator. It operates at 12 volts and maintains a charging voltage between 13.5 and 14.5 volts.
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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.
- Acura RL:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Acura RL Alternator Failing?
- Common Symptoms of a Bad Alternator
- Known Issue: Power Steering Fluid Leaks
- Choosing the Right Aftermarket Alternator
- Tier 1: Premium Aftermarket (Highest Quality)
- Tier 2: Quality Aftermarket (Good Value)
- Tier 3: Economy Brands (Budget-Focused)
- New vs. Remanufactured
- How Much Does an Acura RL Alternator Replacement Cost?
- Frequently Asked Questions (FAQ)
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