The 2012-2016 Mercedes-Benz GL 63 AMG (X166) is a luxury SUV that pairs high-performance with spacious comfort. Powered by a twin-turbo V8 engine, this premium model offers exhilarating acceleration, advanced features, and enough space for a full family. However, despite its exceptional engineering, it’s not without its share of common issues. In this article, we’ll examine the most frequently reported problems with the GL 63 AMG, offer tips for what to watch for when buying, and analyze the ongoing costs of ownership.
Common Problems with the 2012-2016 Mercedes-Benz GL 63 AMG (X166)
1. Air Suspension System Failures
The GL 63 AMG’s air suspension system, known as AIRMATIC, is designed to enhance ride quality and handling by adjusting the height and stiffness based on driving conditions. However, this system is one of the most common sources of issues in this model. Over time, components like the air struts, compressor, and valves can degrade, leading to suspension sagging, uneven ride height, or a rough ride.
Signs and Prevention: Warning signs of suspension issues include sagging, especially when parked, excessive bouncing, and a noticeably rough ride. If the car leans to one side or shows a "suspension malfunction" warning, this usually indicates a failure in the air suspension. Replacing air suspension parts can be costly, so consider a comprehensive inspection and inquire if the seller has already serviced or replaced suspension components.
2. Turbocharger Reliability and Oil Leaks
Equipped with a powerful 5.5-liter twin-turbo V8 engine, the GL 63 AMG delivers impressive power, but turbocharger issues are relatively common, especially with high mileage. Over time, the turbocharger’s seals can wear out, leading to oil leaks, reduced performance, and, in extreme cases, turbocharger failure. Oil leaks can also cause secondary issues, such as fouled spark plugs and exhaust smoke.
Signs and Prevention: Symptoms of turbocharger problems include reduced acceleration, excessive smoke from the exhaust (often blue or white), and the smell of burning oil. During a test drive, listen for whining or whistling sounds from the engine at higher RPMs, as these may suggest turbo issues. Ensuring regular oil changes and using high-quality synthetic oil can help prolong turbocharger life.
3. Engine Oil Leaks and Consumption
The GL 63 AMG’s engine is known to be susceptible to oil leaks, often from the valve cover gaskets and the rear main seal. Many owners report increased oil consumption, requiring frequent top-offs between oil changes. Over time, undetected oil leaks can lead to reduced engine performance and increased risk of wear on engine components.
Signs and Prevention: Visible oil spots under the vehicle or a burning oil smell after driving can indicate an oil leak. Check the engine bay for any oil residue around the valve covers or undercarriage, especially around the rear main seal. Regular oil checks and routine inspections are essential for early detection. For buyers, ensure the seller provides a history of any previous oil leak repairs.
4. Transmission Jerking and Delayed Shifts
The GL 63 AMG’s 7-speed automatic transmission, while generally robust, is prone to issues such as jerking, delayed shifts, and occasional slipping. Many drivers report that shifts can feel harsh, especially when accelerating or downshifting at low speeds. These symptoms may be related to software calibration, low transmission fluid, or mechanical wear within the transmission.
Signs and Prevention: A test drive can reveal transmission issues—any hesitation, jerking, or hard shifts should raise a red flag. Having the transmission fluid checked for cleanliness and proper levels can help, as low or dirty fluid can exacerbate issues. Additionally, some owners find that periodic software updates help improve shift smoothness, so checking the vehicle’s software update history is useful.
5. Timing Chain and Tensioner Wear
Mercedes-Benz vehicles, including the GL 63 AMG, have a known issue with timing chain wear and tensioner failure. Over time, the timing chain may stretch or the tensioner may lose effectiveness, leading to a rattling noise at startup and, in some cases, performance issues. If not addressed, this problem can lead to costly engine repairs or even engine failure.
Signs and Prevention: Listen for a rattling or ticking noise from the engine, especially on startup. If the sound persists, it may indicate a worn timing chain or tensioner. Replacing a timing chain is a complex and expensive repair, so be sure to ask the seller if any timing chain maintenance has been performed.
6. Brake System Wear and High Maintenance Costs
Due to its powerful engine and high-performance characteristics, the GL 63 AMG’s brake system endures substantial stress. Brake pads, discs, and even calipers can wear out faster than on typical vehicles, leading to more frequent replacements. Brakes may begin to squeak or feel less responsive over time, especially if subjected to heavy or aggressive use.
Signs and Prevention: Check the braking system for smoothness and responsiveness. Squealing noises and vibrations when braking can indicate worn pads or discs. Owners should budget for frequent brake maintenance, and potential buyers should verify the condition of the brakes, as replacing AMG-grade brake components can be quite costly.
7. Electronics and Infotainment System Issues
The GL 63 AMG is equipped with a sophisticated array of electronics, including an advanced infotainment system. However, some owners report glitches in the COMAND system, such as freezing, slow response times, and Bluetooth connectivity problems. Additionally, electrical malfunctions can affect seat adjustments, door locks, and climate control.
Signs and Prevention: During a test drive, thoroughly test the infotainment system, Bluetooth connectivity, and other electronic features. Make sure to adjust the seats, check door locks, and test all power functions. Software updates may resolve some issues, but more severe electrical faults may require diagnostics and repairs at a Mercedes specialist.
Buying Tips: What to Look for in a 2012-2016 Mercedes-Benz GL 63 AMG (X166)
Complete Service History: Since this model requires meticulous maintenance, it’s essential to verify that all scheduled services have been completed, particularly any work related to the air suspension, turbocharger, and transmission. Service records from a certified Mercedes-Benz dealer or AMG specialist are ideal.
Warranty or Extended Coverage: If possible, look for a vehicle with remaining factory warranty or extended coverage. Many common repairs for the GL 63 AMG are costly, and warranty coverage can help mitigate these expenses.
Thorough Test Drive: When test-driving the GL 63 AMG, test both city and highway speeds to check for any transmission delays, suspension comfort, and engine performance. Be mindful of unusual noises, warning lights, or inconsistent shifts.
Check for Recalls and Software Updates: Mercedes-Benz has issued occasional recalls and software updates for the GL 63 AMG. Ensure the seller has completed these, as they can improve performance and address known issues.
Cost of Ownership: Is the 2012-2016 Mercedes-Benz GL 63 AMG Expensive to Own?
Fuel Costs
The GL 63 AMG’s twin-turbo V8 is both powerful and fuel-hungry, with fuel economy ratings of around 13 MPG city and 17 MPG highway. Fuel costs for this model will be high, particularly for those who drive frequently or have long commutes. Premium fuel is required for optimal performance, further adding to costs.
Maintenance and Repair Costs
Due to the complexity and high-performance components of the GL 63 AMG, maintenance and repair costs are significantly higher than for most standard SUVs. Routine oil changes, brake services, and air suspension inspections are necessary to keep the vehicle running smoothly, and they often come at a premium due to the AMG brand.
Replacing components like the air suspension system or turbocharger can be extremely expensive, so planning for periodic repair costs is essential.
Insurance and Depreciation
Insurance premiums for the GL 63 AMG are generally higher due to its performance capabilities and repair costs. Depreciation is also a factor, as luxury SUVs tend to lose value relatively quickly. However, models with complete service histories and in excellent condition can retain value better within the used market.
Potential Extra Costs
Since the GL 63 AMG is a luxury model, prospective owners should budget for higher-than-average costs associated with luxury features. From premium tire replacements to periodic detailing and more, luxury ownership comes with additional expenses beyond typical maintenance.
Conclusion
The 2012-2016 Mercedes-Benz GL 63 AMG (X166) delivers a unique combination of power, luxury, and family-friendly space. However, its high-performance nature and complex systems make it prone to several common issues, from air suspension failures and turbocharger wear to electronic glitches and transmission concerns. Prospective buyers should ensure a thorough inspection and complete service history, while current owners should budget for regular maintenance and be prepared for potential repairs. For those willing to invest in its upkeep, the GL 63 AMG offers a thrilling and luxurious driving experience that few SUVs can match.