The Mercedes GL/GLS models represent the top-echelon of Mercedes full-size luxury SUVs made for uttermost comfort for all seven passengers. These cars are large, wide, heavy, and long which means that they are not the easiest cars to drive, but they are some of the most comfortable ones.
With such great mass comes a few distinct caveats, many of which are directly associated with all the issues GL450 models experience. The GL450 was in production between 2007 and 2017, and in that time the GL has continuously been improving until it was replaced with the GLS.
The first generation of the GL450 (X164) was introduced in 2006, and it mainly suffers from airbag issues, suspension issues, and steering issues. The second generation of the GLE450 (X166) was introduced in 2013. This GL450 model is a lot more up to date and it is more reliable than the first generation.
The most annoying issues that plague the 2nd generation of the GL450 are electrical issues, seat-related issues, and engine issues. It’s safe to say that all GL models are complex and expensive to maintain which makes them prone to all sorts of issues if they are not taken care of properly.
Mercedes GL450 (X164) airbag issues
The X164 GL450 was also part of the dreaded Mercedes Takata recall which included all sorts of faulty airbags and faulty airbag deployment systems in virtually all Mercedes models from that era. The issue here is that so many Mercedes models were affected, thus there are still many Mercedes models with unresolved air-bag-related issues out and about.
If you are interested in buying a used X164 GL450, or any other Mercedes from that era, you ought to investigate if the car you are looking at has all of these issues sorted. If not, you are risking potentially deadly consequences as you are never confident in your airbags.
Mercedes GL450 (X164) suspension issues
The GL450 is the flagship Mercedes seven-seater full-size SUV which means that it gets the Mercedes AIRMATIC air suspension system. This system is not as bad as everyone thinks, yet that is only the case if the system was indeed maintained properly.
The most common GL450 air suspension issues include sinking and air compressor issues. Sometimes the pressure starts leaking which results in the car either completely sinking or sinking to one side or the other.
Mercedes GL450 (X164) steering issues
Early GL450 models are known to sometimes experience fairly serious issues with the steering system. Issues such as power steering locking during driving are not something you want to experience, but sadly many GL450 owners did.
Furthermore, many owners also reported a heavy steering wheel and inconsistent steering wheel power assistance.
Mercedes GL450 (X166) electrical issues
The second generation of the GL450 seems to be a lot more reliable than the first-generation model, but it’s safe to say that even this full-size SUV is not without its share of issues. One of the most common X166 issues are electrical, such as a faulty blind spot assist system, wiring harness issues, or some particularly interesting water-related issues.
All in all, these come in a variety of different issues which means that you may experience issues with your windshield wiper while another owner may experience issues with some other electrical item.
Both the first and especially the second generation of the GL450 are known for having completely stupid headrest-related issues. As the GL450 is mostly being used for chauffeuring large families, many owners complained that they are unable to completely remove the 2nd-row headrests in order to properly mount a child seat.
Owners state that these headrests make younger second-row passengers uncomfortable while others state that the GL450 is extremely unsafe because of this. Mercedes never fully responded on this issue, nor do they offer a fix.
Mercedes GL450 (X166) engine issues
The GL450 is not a car known for a huge amount of engine-related issues, but some owners reported oil leaks, occasional engine cooling-related issues, or radiator leaks. There are some instances in which few owners complained about the engine completely dying even without the car crossing the 50k mile mark.
Most reports indicated that these were down to human error at the assembly plant and that these are not associated with all GL450 models. All in all, the engines in these behemoths are relatively reliable, but only if you maintain them correctly and in due time.
Is the X164 GL450 better than the X166 GLE450?
The later X166 GLE450 is the better car to buy because it is a lot more modern and because it is also a lot more reliable. The first-gen X164 GL is now a relatively old car which means that many potential issues might arise from owning such a complex and old car.
On the other hand, the X166 is still reasonably up to date which means that it can be had with the majority of modern-day technology. The GLS was actually only a refreshed X166 which means that the last generation of the GL is more or less the same as the first generation of the GLS.
Is the Mercedes GL450 expensive to maintain?
All premium German luxury large SUVs are expensive to maintain because they use large engines, large tires, large brakes and they are fairly heavy which means that all of these need to manage the weight. Many sites state that you should be prepared to pay upwards of $2,000 each year for GL maintenance.
This comes as no surprise as these cars are large and packed with all sorts of technology and comfort gadgets.
Is the Mercedes GL450 safe?
Both generations of the GL450 are safe, but the newer X166 generation is even safer. Mercedes tried their best to make these cars as safe as possible because they are commonly being used for family transporting duties. However, the Takata recall and all the seat-related issues do ruin the image a bit.
Either way, if you are interested in buying a used GL model, be sure to take it for a thorough pre-purchase inspection and make sure that all of the aforementioned issues are addressed during that inspection.