The Mercedes-Benz SUV has a reputation for bulletproof reliability. This makes sense, considering the boxy Mercedes “G Wagon” was designed for military use in 1979. But the mighty G Wagon isn’t without its problems, either. Here are the most common problems reported by G-Class owners to the RepairPal website.
- Faulty door lock and window switch
- Faulty oil level sensor or crankshaft position sensor
- Faulty brake light switch
Failure of the door lock, window switch and door handle
The G Wagon door lock, the door handle, and that’s exactly what it sounds like. G Wagon SUV owners report that one or all of these components fail, leaving a stuck window or a door that can only be opened from the inside. From the owner’s comments, it appears that these problems aren’t always connected, but instead that all of these components are simply prone to occasional failure in early G-Class SUVs.
has recorded 34 complaints of this problem on G 500 from 2002 to 2008, with an average mileage of 97,028. It also received 15 other reports of the same problem from G 55 AMG SUV owners from 2003 to 2010, with an average mileage of 89,800.
While these problems seem frustrating, none of them threaten drivetrain reliability: A broken window motor won’t leave you stranded. RepairPal estimates the average repair cost will be $110-$139, for each instance of each problem.
Oil level sensor or crankshaft position fault sensors
Two different G Wagon engine sensors have been known to fail, with very different results. These problems show up on both regular SUVs and the AMG-tuned G Wagon.
The first sensor is something called a crankshaft position sensor. Not to get too technical, but this is essentially a magnetic pick up that the engine control module uses to tell exactly where the crankshaft is. The position of the crankshaft affects processes such as ignition and valve opening, so the ECM will not let the engine run unless the sensor is working. The good news is that this feature can prevent very costly engine damage, but the bad news is that a simple sensor failure can leave you stranded.
A total of 12 Mercedes-Benz G500 owners reported this problem on SUVs from 2002 to 2008. The sensor failed at 162,500 miles on average, but can fail as early as 100,000 miles. Also, 10 Mercedes-AMG G55 owners have reported the exact same issue. AMGs affected include 2003 through 2010. This issue affects the AMG tuned G Wagon engine at 101,500 miles on average, but can rear its ugly head at just 74,000 miles.
The second problematic sensor is the oil level sensor. When it goes bad, it can leak a trickle of oil and even burn on the hot engine, resulting in a constant cloud of obnoxious smoke. Nine G500 owners from 2002 to 2008 reported this problem occurring at approximately 158,000 miles. Ten G55 AMG owners have reported this issue on 2003-2011 SUVs, showing up as early as 7,700 miles.
Both problems seem frustrating. But honestly, an engine that smokes or won’t start can be expensive to fix. A failed sensor is one of the simplest and cheapest causes to address.
Faulty brake light switch
Finally, a brake light switch failure is another problem reported by multiple owners. Luckily this is a small electrical switch under the brake light and when it fails, the SUV will turn on a warning light on the dashboard. It’s a relatively quick item for a technician or dealer to tackle.
Overall, 13 owners of Mercedes G500 SUVs, model year 2002 to 2008, reported this. The average mileage before the sensor failed was 87,000. Additionally, eight owners of 2003-2010 G55 AMGs have reported the same problem.
So there you have it, many of the Mercedes G Wagon problems most often reported on the RepairPal website. For comparison, other SUVs have problems with dozens or hundreds of reported cases. RepairPal gave the G-Class SUV an “above average” reliability rating of 3.5 out of 5.
Next, find out or watch the most common G tank problems in the video below:
You can find out all about the reliability of the G-Class in this next video:
You can see some of critic Doug DeMuro’s issues with the last generation G Wagon’s ergonomics and design in this final video:
