6 Most Common Problems With Mercedes ML350 (Explained)

Introduced by Mercedes in 2002 and discontinued after the 2015 model year, the ML350 remains a hugely popular SUV.

It’s not hard to imagine why either, it’s luxurious, practical and very comfortable.

Sadly though, no vehicle is perfect and in this article we will highlight some of the ML’s biggest complaints.

1. Airbag Problems

On Car Problem Zoo, a site dedicated to owner feedback, the most commonly reported ML350 complaint is due to its airbags.

These complaints are mostly linked to the infamous Takata recalls which affected tens of millions of vehicles, not just the ML.

The Japanese-made airbags weren’t fit for purpose to put it mildly – when exposed to humidity and high heat the airbags were known to explode when deployed causing serious injury and in some cases death.

To make matters worse, many owners were left waiting for an unreasonable amount of time for parts to arrive at their dealership and for the problem to be resolved.

These complaints mostly affect the 2010 and 2011 model years.

Solution

Whether you’re the owner of an ML or looking to buy a used one – always run the VIN on either Mercedes or the NHTSA website to see if the vehicle has been subject to a recall.

Due to the severity of this problem, it is imperative that you leave this to the dealership to fix.

2. Faulty Camshaft Adjuster Solenoid

According to Repair Pal, the most commonly reported ML350 problem is a faulty camshaft adjuster solenoid.

Model years worst affected include: 2006, 2007, 2008, 2012

The ML350 uses a variable valve timing (VVT) system which is a type of piston engine technology that deliberately delivers inconsistent timing of the intake and exhaust valves.

The camshaft adjuster solenoid is responsible for allowing oil to adequately flow through the VVT system upon its engagement.

Typically the first sign that the camshaft adjuster solenoid has failed, is the check engine light comes on, other symptoms include:

• Lowered fuel efficiency
• Contaminated engine oil
• Rough idling
• Rough acceleration
• Low engine power

The premature failure of the camshaft adjuster solenoid was common on other Mercedes vehicles and not just the ML.

Here’s what some unhappy ML owners had to say on the matter:

Check Engine Light stays on. First I was told the camshaft adjuster solenoids needed to be replaced – I had all 4 replaced. The Check Engine Light came back on the next time I used the vehicle. Now I’m being told the balance shaft gears are wearing and the balance shaft needs to be replaced – estimate is $5,500. Mercedes is aware of the issues but has not issued a recall. From things I’ve read on the internet, a national class action complaint is being prepared – let’s hope the courts can force Mercedes to “do the right thing”

Solution

If the camshaft adjuster sensor has failed then it will need to be replaced, it’s not entirely clear whether or not there is a recall for this issue, if in doubt run the VIN and/or speak to your dealership.

If you have to pay for this out of your own pocket, using an independent repair shop will be cheaper than using Mercedes.

3. Rough Shifting

A commonly reported complaint of Mercedes ML350s with automatic transmissions is rough shifting.

This has been reported on ML350 model years from 2003 all the way up to 2015.

For ML’s equipped with a 7-speed automatic transmission, the rough shifting is most noticeable when:

• Going up from first to second gear
• Going down from third to second or second to first gear
• The vehicle is cold

According to owners, this problem is often accompanied by loud clunking and grinding sounds.

If you’re looking at buying a used ML350, ask the seller to leave the vehicle cold and take it for a test drive paying close attention to how smooth the gear shifts are.

Solution

Rough shifting is a transmission problem.

In some instances, owners have been able to fix this with nothing more than a transmission software update.

Other reports suggest it’s due to an internal component failure of which Mercedes has released updated parts.

In which case the transmission will need to be removed and disassembled to carry out the repairs.

4. Engine Stalling

Engine stalling isn’t widespread on the ML350 although there have been enough complaints that it’s worth mentioning.

Stalling is when the engine cuts out.

This has been mostly reported on ML model from 2006 – 2012.

One driver had this to say:

“My ML350 has only 65000 miles and was working fine then the engine stalled and now needs a new engine!! Stalled on the highway suddenly and had to be towed to shop they want to replace engine”

Solution

In some instances, this issue has been linked to the failure of the engine control module pins which is easy enough to remedy and shouldn’t require a new ECM.

In other cases the vehicle has required a new engine, which is one of the most expensive repairs you can get.

According to Repair Pal, the 3 most common causes of stalling on an ML350 are related to:

1. Fuel system
2. Air intake system
3. Ignition system

5. Brake Light Warning Message

Reported numerous times on Repair Pal, ML owners have described seeing the brake light warning message for a burnt-out bulb being displayed.

This problem has been reported on model years from 2003 all the way up to 2015.

This issue has been linked to the tail lamp housing which is prone to melting when it gets hot.

Once the housing has melted the bulb will no longer work due to poor electrical connections.

In other instances, the bulb works fine however the warning message is displayed – some owners describe having to continuously replace the bulb.

The brake light warning message has also been linked to improper grounding of the brake light socket.

Solution

In most instances the lamp housing will need to be replaced, this can cost upwards of $250 to fix.

6. Power Steering Problems

There have been numerous complaints pertaining to the ML350’s steering, owners have reported that whilst driving at moderate to high speeds, the steering was not controllable and there was a loss of power steering – this is often accompanied by steering fluid leakage.

This problem has been reported 34 times on Car Problem Zoo and 104 times on Repair Pal. It mostly seems to be linked with 2006 – 2008 models although it has been linked with models as early as 2003 and as late as 2013.

Owners have reported that their ML350’s steering rack leaks power steering fluid and they’ve noticed puddles of leakage on their garage floor.

Other owners haven’t been lucky enough to spot the early warning signs and have been unfortunate enough to be out driving when their power steering has failed.

Solution

In many instances the steering rack will need to be replaced which can cost upwards of $2000, although there has been recall campaigns for steering problems too which should be fixed by the dealer for free.

Related: How Long Do Mercedes ML350 Last? (12 Important Facts)

Mercedes ML350 Model Years With the Most Problems

Based on data obtained from Car Problem Zoo, here are the most and least problematic years for the ML350:

The most problematic years are:

1. 2006 – 208 Problems
2. 2011 – 103 Problems
3. 2010 – 101 Problems

And the least problematic years are:

1. 2001 – 3 Problems
2. 2005 – 24 Problems
3. 2015 – 40 Problems

Source: Car Problem Zoo

Mercedes ML350 Pros and Cons

If you’re considering a Mercedes ML350 as your next car you might be wondering what its strengths and weaknesses are…

Pros

• Elegant cabin
• Ultra-comfortable ride
• Classy exterior design
• Powerful engine

Cons

• Repairs and maintenance are expensive
• Suspension is designed more for comfort than handling

Mercedes ML350 Reliability Compared to Similar Cars

Consumer Reports rankings detailed below is based on the model’s newest three years.

Source: Consumer Reports

Mercedes ML350 Used Value

We’ve taken a look on Car Gurus to gauge the resale value of a Mercedes ML350, below are typical asking prices for each model year.

Note: Used model prices will vary depending on trim level.

Source: Car Gurus

What Do Owners Like and Dislike About the Mercedes ML350?

Based on owner feedback from the Kelley Blue Book site here are what real-life owners love and hate about the Mercedes ML350.

Likes

1. Great looks
2. Fuel economy
3. Smooth and steady on the road
4. Minimal noise
5. Lives up to the great reviews
6. Comfortable
7. Reliable
8. Technology

Dislikes

1. Discontinued production of diesel variants
2. Expensive maintenance and repair costs
3. Uncomfortable rear seating
4. Can only accommodate 5 people
5. A little heavy

Owners Reviews

“This one is a gem. the power is great – it will jump when you need it to. the gas mileage is wonderful, and it doesn’t bog down in the snow. I may keep this car forever.”

Source: Kelley Blue Book

“Bought this vehicle new in 2013. It still looks new, with its design holding to look great next to our neighbor’s 2020 GLE43. We would buy another one if MB still offered this outstanding 3L turbo/diesel: 24 mpg city; 32 MPG hwy, with more torque than ML550.”

Source: Kelley Blue Book

“115K miles on this car and it’s running great, remains comfortable and continues to get excellent fuel mileage for such a large car – love the diesel.”  

Source: Edmunds

How Reliable Are Mercedes Cars?

According to a recent report from Consumer Reports, Mercedes are ranked the 23rd most reliable car manufacturer out of 28 brands.

Source: Consumer Reports

Sources

https://www.consumerreports.org/cars/mercedes-benz/m-class/

https://www.cargurus.com/Cars/t-Used-Mercedes-Benz-M-Class-ML-350-t38348

https://www.kbb.com/mercedes-benz/m-class/

https://www.edmunds.com/mercedes-benz/m-class/2015/review/

https://www.carcomplaints.com/Mercedes-Benz/ML350/

https://www.carproblemzoo.com/mercedesbenz/ml350/