Mercedes-Benz ML500: common faults & what to check
Thinking about buying a used Mercedes-Benz ML500 (1997–2011) in New Zealand? We've documented 6 known faults for this model spanning engine, transmission, suspension, and electrical. Each researched and verified before it's published. The most serious issues here are rated critical. Every one is listed below with its symptoms and repair cost, and each has its own page with where to look and what to ask the seller. Free, no account needed.
Check this exact Mercedes-Benz ML500
- Odometer history
- Money owing
- Reported stolen
- Ownership history
6
Critical
$1,500–$6,000
4
Which Mercedes-Benz ML500 are you looking at?
Engine not documented
Now narrow it to the engine
Start your free check on this Mercedes-Benz ML500
Pick the engine above first: the ML500 came with 6, and without it the report has to show all of their faults. Pick the engine
Can't confirm for this car
Mercedes-Benz ML500
Nothing has been narrowed yet, so nothing below is a claim about a particular car. Pick a year and an engine to see which faults apply.
Tell us the engine, or check the engine code on the car, before relying on this.
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What to look out for
Serious issue
Check engine serial number against the Mercedes published threshold (below 30468993 on M272).
M272/M273 Balance Shaft Sprocket Premature Wear
The M272 V6 and M273 V8 engines used a composite plastic balance shaft idler gear sprocket that wears prematurely. As teeth degrade, the timing chain slackens and the right-bank camshafts fall out of time. A class action lawsuit was settled by Mercedes-Benz in 2011 for approximately USD $4,000 per affected vehicle. Engines with serial numbers below 30468993 on M272 are most commonly affected, though failures outside this range are also documented.
What you would notice
Costly issue
Park on level ground overnight and check all four corners for sag in the morning.
Airmatic Air Suspension Strut Leak and Compressor Failure
The W164 Airmatic system is prone to air spring and strut leaks at the upper crimp rings and top seals as rubber perishes with age. The compressor runs excessively to compensate for leaking struts and eventually burns out, often blowing the 40-amp Airmatic fuse. Valve block solenoids also develop internal leaks. Ride height sensor rods become brittle and snap, causing persistent ride height fault messages.
What you would notice
Costly issue
Inspect beneath the vehicle for oil staining at the transfer case front and rear output seals.
W163 Transfer Case Internal Wear and Seal Leaks
The W163 four-wheel-drive transfer case is prone to internal chain stretch and bearing wear, accelerated by neglected fluid changes. Front and rear output shaft seals are also known to leak, causing oil loss that accelerates internal wear. When the transfer case chain fails, complete replacement is typically necessary. Low-range transfer case motor actuator failure is also documented on W163.
What you would notice
Costly issue
Scan for transmission fault codes before purchase.
7G-Tronic (722.9) Conductor Plate and Valve Body Failure
The 722.9 seven-speed automatic transmission uses a solenoid conductor plate embedded in the valve body that is prone to internal failure, particularly on early VGS1-coded units fitted from 2005–2008. Extended service intervals with degraded transmission fluid accelerate solenoid wear. Both the conductor plate and valve body may require replacement together for a lasting repair.
What you would notice
Costly issue
Start the engine cold and observe exhaust for blue smoke in the first 30 seconds.
M112/M113 Valve Stem Seal Wear and Oil Leaks
The M112 3.2/3.7-litre V6 and M113 5.0-litre V8 petrol engines develop oil consumption from worn valve stem seals and are known to leak at the oil heat exchanger seal and timing cover O-ring. These issues appear progressively with age. The engines are considered fundamentally reliable but require attention to oil levels and seal condition as mileage climbs.
What you would notice
Costly issue
Check instrument cluster for any combination of ABS, ESP, ETS, or BAS warning lights.
ABS/ESP Brake Pressure Sensor Connector Corrosion
Green corrosion develops inside the brake pressure sensor (B34) wire harness connector on W163 vehicles, causing intermittent and eventually permanent failure of the ABS, ESP, ETS, and BAS systems. Moisture ingress into the exposed connector housing drives the corrosion. The fault causes multiple simultaneous warning lights and in some cases causes the speedometer to drop to zero and the transmission to behave erratically. Fault code C1141 is the primary indicator.
What you would notice
See all 6 documented issues
Depends on which engine this Mercedes-Benz ML500 has — 6
Engine, transmission & cooling
01M272/M273 Balance Shaft Sprocket Premature Wear
Can't confirm for this car
Can't confirm for this car
The M272 V6 and M273 V8 engines used a composite plastic balance shaft idler gear sprocket that wears prematurely. As teeth degrade, the timing chain slackens and the right-bank camshafts fall out of time. A class action lawsuit was settled by Mercedes-Benz in 2011 for approximately USD $4,000 per affected vehicle. Engines with serial numbers below 30468993 on M272 are most commonly affected, though failures outside this range are also documented.
Symptoms to notice
What to check
Ask the seller
02W163 Transfer Case Internal Wear and Seal Leaks
Can't confirm for this car
Can't confirm for this car
The W163 four-wheel-drive transfer case is prone to internal chain stretch and bearing wear, accelerated by neglected fluid changes. Front and rear output shaft seals are also known to leak, causing oil loss that accelerates internal wear. When the transfer case chain fails, complete replacement is typically necessary. Low-range transfer case motor actuator failure is also documented on W163.
Symptoms to notice
What to check
Ask the seller
037G-Tronic (722.9) Conductor Plate and Valve Body Failure
Can't confirm for this car
Can't confirm for this car
The 722.9 seven-speed automatic transmission uses a solenoid conductor plate embedded in the valve body that is prone to internal failure, particularly on early VGS1-coded units fitted from 2005–2008. Extended service intervals with degraded transmission fluid accelerate solenoid wear. Both the conductor plate and valve body may require replacement together for a lasting repair.
Symptoms to notice
What to check
Ask the seller
04M112/M113 Valve Stem Seal Wear and Oil Leaks
Can't confirm for this car
Can't confirm for this car
The M112 3.2/3.7-litre V6 and M113 5.0-litre V8 petrol engines develop oil consumption from worn valve stem seals and are known to leak at the oil heat exchanger seal and timing cover O-ring. These issues appear progressively with age. The engines are considered fundamentally reliable but require attention to oil levels and seal condition as mileage climbs.
Symptoms to notice
What to check
Ask the seller
Electrical
01ABS/ESP Brake Pressure Sensor Connector Corrosion
Can't confirm for this car
Can't confirm for this car
Green corrosion develops inside the brake pressure sensor (B34) wire harness connector on W163 vehicles, causing intermittent and eventually permanent failure of the ABS, ESP, ETS, and BAS systems. Moisture ingress into the exposed connector housing drives the corrosion. The fault causes multiple simultaneous warning lights and in some cases causes the speedometer to drop to zero and the transmission to behave erratically. Fault code C1141 is the primary indicator.
Symptoms to notice
What to check
Ask the seller
Body, brakes, suspension & interior
01Airmatic Air Suspension Strut Leak and Compressor Failure
Can't confirm for this car
Can't confirm for this car
The W164 Airmatic system is prone to air spring and strut leaks at the upper crimp rings and top seals as rubber perishes with age. The compressor runs excessively to compensate for leaking struts and eventually burns out, often blowing the 40-amp Airmatic fuse. Valve block solenoids also develop internal leaks. Ride height sensor rods become brittle and snap, causing persistent ride height fault messages.
Symptoms to notice
What to check
Ask the seller
Other Mercedes-Benz models
Mercedes-Benz ML500 buyer questions
Is the Mercedes-Benz ML500 reliable?
Like any used car, it depends on the specific example and its service history. Across the 6 documented faults for the Mercedes-Benz ML500, the recurring problem areas are engine, transmission, and suspension. A Mercedes-Benz ML500 with a full service history and no signs of the issues listed on this page can be a sound buy but each one needs to be checked individually before you commit.
What are the most common problems with a used Mercedes-Benz ML500?
We've catalogued 6 known faults for the Mercedes-Benz ML500, covering engine, transmission, and suspension. All 6 are written out in full on this page, with the symptoms to notice, what to inspect, and typical repair costs for each. Free to read, no account needed.
How much do repairs cost on a Mercedes-Benz ML500?
Most single repairs on the Mercedes-Benz ML500 fall between $1,500–$6,000 at NZ independent-workshop rates. Some of the 6 documented faults cost less and a few cost considerably more, and no one car needs them all. Knowing which ones to look for before you view is what lets you negotiate the price down or walk away.
Should I get a pre-purchase inspection on a Mercedes-Benz ML500?
Yes. A Mercedes-Benz ML500 inspection focused on its known weak points is the single best way to avoid an expensive mistake. KickTyres gives you a guided, model-specific inspection plus a market valuation and negotiation figure for $24.90 far less than the cost of missing one of the faults on this page.