Mercedes-Benz ML W163
Weaknesses, engine ratings and buying advice
The M-Class W163 (1997–2005) was Mercedes' first SUV — built in Tuscaloosa, Alabama, not Stuttgart. Early years were a quality disaster (build quality, rust, electrics). Only the 2002 facelift brought real improvement. Pre-2002 only for DIY mechanics.
Engine choice: M112 (ML 320 160 kW / ML 350 173 kW) is the sensible V6 — SOHC, unremarkable but durable. M113 (ML 430 200 kW / ML 500 215 kW / AMG ML 55 255 kW) is the V8 — thirsty (15–18 l/100 km) but solid mechanically. OM612 (ML 270 CDI, 120 kW) is the most common — 5-cylinder diesel, economical but turbo and transmission are expensive topics. OM628 (ML 400 CDI, 184 kW) is the V8 diesel — brutally fast but the automatic wasn't designed for its torque.
Rust is THE topic: brake lines corrode (recall 2004–2005), structural members, sills, wheel arches. Suspension: springs break above average, tie rods worn from 80,000 km. Automatic (5-speed): oil leaks, rough shifts — oil change every 60,000 km mandatory.
Test-drive checklist: Rust on brake lines and underbody (lift mandatory!), automatic shifting quality, 4WD LOW range test, springs for cracks, turbo whistle on 270 CDI.
2026 market: ML 270 CDI from $2,000–5,500. ML 350/500 $3,500–9,000. AMG ML 55 $9,000–16,500 (collector). Insider pick: ML 350 (M112) from 2002 facelift with documented oil changes and rust-free underbody.
250 PS
ML 400 CDI · Diesel
V8 Diesel in Off-Road Form — Rare, Sonorous, Serious
Fun to Drive!163–231 PS
2.7L 5-Zyl Diesel Diesel
6 weaknesses
Stay Away!Generations
Engine Overview
The Mercedes-Benz ML W163 is available with 7 engine variants — from 163 to 517 hp.
Five-cylinder diesel with common rail. Unusual cylinder count, good balance of power and economy. Prone to blocked swirl flaps.
- !! "Black Death" -- injector seal failure with tar formation from 150,000 km
The most notorious problem in the OM612/OM646 CDI family: failing injector sealing rings allow combustion gases to escape. A black, tar-like mass forms around the injectors.
Symptoms: Black tar visible around injectors, hissing or knocking under load, diesel smell in interior - !! EGR cooler fails -- coolant in intake from 150,000 km
The EGR cooler on the OM612 can develop internal leaks and introduce coolant into the intake. This leads to white smoke, coolant loss and in the worst case hydro-lock.
Symptoms: White smoke from exhaust, coolant loss, sweet smell from exhaust, coolant in air filter housing - !! Cylinder head crack -- coolant loss under load from 200,000 km
Cylinder head cracks can form in the OM612 between two valves, only becoming visible under load.
Symptoms: Coolant loss without visible leak, white smoke, bubbling in coolant reservoir under load.
+ 3 more engine weaknesses + vehicle weaknesses
Mercedes' first V8 diesel in automotive history — world premiere in 2000. Common rail at 1,350 bar, two turbos in tandem, 4.0 litres. Result: 570 Nm from 1,600 rpm, a character that no petrol engine of that class could match in composure at the time. Maintenance-intensive. Timing chain and tensioners are due around 150,000 km — not optional, mandatory. The right-hand turbocharger is the known weakness and will need replacing sooner or later. Injectors and high-pressure pump dislike poor-quality fuel. Oil every 10,000 km, Mercedes approval 229.51 or better — the engine does not forgive cutting corners on lubricant. With thorough maintenance 300,000 km is realistic. None of this is cheap, but anyone who buys a V8 diesel budgets for it.
- !! Timing chain and tensioner worn from 160,000 km
Timing chain stretches from around 150,000 km; chain tensioner and guides wear. Cold-start rattling is a typical early warning. Left untreated, chain jump and total engine failure threaten.
Symptoms: Metallic rattling on cold start that subsides after 3-5 seconds. With severe stretch also audible at operating temperature. - !! Bi-turbo failure (right turbocharger preferentially) from 100,000 km
The right turbocharger is the classic weak point of the OM628. Total failure of both turbos from around 90,000-100,000 km has been documented. Repair on the V8 diesel is correspondingly labour-intensive.
Symptoms: Significant power loss, blue or white smoke from exhaust, whistling noise under load. - !! Coolant loss through cylinder head from 200,000 km
Under extreme pressure loading, head gaskets fail. CO2 enters the cooling system; increased pressure pushes coolant out through the expansion tank. Engine removal required for repair.
Symptoms: Coolant warning light, coolant overflows from expansion tank, coolant level drops continuously.
+ 3 more engine weaknesses + vehicle weaknesses
Naturally aspirated V8 in three displacements from 4.3 to 5.5 litres — old-school character with no turbo lag. Linear power delivery, deep rumble from 2,000 rpm building to a hoarse roar above 5,000. Peak torque at 3,000; beyond that it thins out — yet it's silky in part-throttle and surprisingly economical. Achilles heel is the seals: rear crankshaft oil seal practically universal above 150,000 km (gearbox removal required, 600–900 EUR), valve covers and oil filter housing seep with age. All cheap parts. The one critical point: the rubber damper on the crankshaft pulley hardens with age — when it fails the pulley machines into the sump. Replace preventively every 150,000 km. Oil changes every 10,000 km with 5W-40, 16 spark plugs every 60,000–80,000 km — then 400,000 km is realistic.
- !! Vibration Damper/Pulley — Rubber Hardens from 170,000 km
The rubber damper in the crankshaft pulley hardens with age and can eat into the sump — catastrophic consequential damage. Preventive replacement every 150,000 km strongly recommended.
Symptoms: Unusual vibrations at idle, in worst case metallic scraping from below. Often no prior warning — sudden failure. - !! Rear Crankshaft Seal Leaking from 150,000 km
The rear crankshaft seal is leaking on virtually all M113 engines above 150,000 km. Gearbox removal required — 600–900 EUR workshop costs. If oil creeps into the torque converter it becomes expensive.
Symptoms: Oil drops or oil film visible at the engine-gearbox interface, oil loss without any other apparent leak on the engine. - !! Engine Mounts Worn Prematurely from 90,000 km
Engine mounts can fail before 100,000 km. Practical test: finger between the stabiliser bar and front sump — no clearance means the mount is dead. Not visually checkable without removal.
Symptoms: Vibrations in interior especially at idle, dull rumbling on acceleration, in worst case contact between engine and bodywork.
+ 7 more engine weaknesses + vehicle weaknesses
Three-valve V6 with individual ignition coils. Smooth and strong. Typical weak points: crankcase breather and intake manifold flaps. High mileages achievable.
- !! Camshaft Adjuster Leaks Oil into Wiring Harness from 130,000 km
The camshaft adjuster solenoid on the M112 develops a leak and draws oil by capillary action into the wiring harness. Oil can migrate as far as the engine ECU and destroy it.
Symptoms: Cold-start rattling that disappears after 1–2 seconds, camshaft adjuster fault code, oil traces at wiring connector, later ECU faults - !! Intake Manifold Vacuum Hose Breaks from 120,000 km
The vacuum hose for the variable intake manifold on the M112 becomes brittle and breaks. The swirl flaps stick. The hose is not available individually — the entire intake manifold is needed.
Symptoms: Power drop, slight hesitation at part throttle, engine runs but without full power - !! Valve Cover Gasket and Front Cover Gasket Leaking from 130,000 km
On the M112 V6 the valve cover gaskets become porous over time. Especially the rubber seals on the front cover between the timing cover and engine block fail on virtually all high-mileage M112 engines.
Symptoms: Oil spots on the floor, oil smell after driving, oily engine bay, dropping oil level
+ 4 more engine weaknesses + vehicle weaknesses
Three-valve V6 with individual ignition coils. Smooth and strong. Typical weak points: crankcase breather and intake manifold flaps. High mileages achievable.
- !! Camshaft Adjuster Leaks Oil into Wiring Harness from 130,000 km
The camshaft adjuster solenoid on the M112 develops a leak and draws oil by capillary action into the wiring harness. Oil can migrate as far as the engine ECU and destroy it.
Symptoms: Cold-start rattling that disappears after 1–2 seconds, camshaft adjuster fault code, oil traces at wiring connector, later ECU faults - !! Intake Manifold Vacuum Hose Breaks from 120,000 km
The vacuum hose for the variable intake manifold on the M112 becomes brittle and breaks. The swirl flaps stick. The hose is not available individually — the entire intake manifold is needed.
Symptoms: Power drop, slight hesitation at part throttle, engine runs but without full power - !! Valve Cover Gasket and Front Cover Gasket Leaking from 130,000 km
On the M112 V6 the valve cover gaskets become porous over time. Especially the rubber seals on the front cover between the timing cover and engine block fail on virtually all high-mileage M112 engines.
Symptoms: Oil spots on the floor, oil smell after driving, oily engine bay, dropping oil level
+ 4 more engine weaknesses + vehicle weaknesses
Naturally aspirated V8 in three displacements from 4.3 to 5.5 litres — old-school character with no turbo lag. Linear power delivery, deep rumble from 2,000 rpm building to a hoarse roar above 5,000. Peak torque at 3,000; beyond that it thins out — yet it's silky in part-throttle and surprisingly economical. Achilles heel is the seals: rear crankshaft oil seal practically universal above 150,000 km (gearbox removal required, 600–900 EUR), valve covers and oil filter housing seep with age. All cheap parts. The one critical point: the rubber damper on the crankshaft pulley hardens with age — when it fails the pulley machines into the sump. Replace preventively every 150,000 km. Oil changes every 10,000 km with 5W-40, 16 spark plugs every 60,000–80,000 km — then 400,000 km is realistic.
- !! Vibration Damper/Pulley — Rubber Hardens from 170,000 km
The rubber damper in the crankshaft pulley hardens with age and can eat into the sump — catastrophic consequential damage. Preventive replacement every 150,000 km strongly recommended.
Symptoms: Unusual vibrations at idle, in worst case metallic scraping from below. Often no prior warning — sudden failure. - !! Rear Crankshaft Seal Leaking from 150,000 km
The rear crankshaft seal is leaking on virtually all M113 engines above 150,000 km. Gearbox removal required — 600–900 EUR workshop costs. If oil creeps into the torque converter it becomes expensive.
Symptoms: Oil drops or oil film visible at the engine-gearbox interface, oil loss without any other apparent leak on the engine. - !! Engine Mounts Worn Prematurely from 90,000 km
Engine mounts can fail before 100,000 km. Practical test: finger between the stabiliser bar and front sump — no clearance means the mount is dead. Not visually checkable without removal.
Symptoms: Vibrations in interior especially at idle, dull rumbling on acceleration, in worst case contact between engine and bodywork.
+ 7 more engine weaknesses + vehicle weaknesses
Naturally aspirated V8 in three displacements from 4.3 to 5.5 litres — old-school character with no turbo lag. Linear power delivery, deep rumble from 2,000 rpm building to a hoarse roar above 5,000. Peak torque at 3,000; beyond that it thins out — yet it's silky in part-throttle and surprisingly economical. Achilles heel is the seals: rear crankshaft oil seal practically universal above 150,000 km (gearbox removal required, 600–900 EUR), valve covers and oil filter housing seep with age. All cheap parts. The one critical point: the rubber damper on the crankshaft pulley hardens with age — when it fails the pulley machines into the sump. Replace preventively every 150,000 km. Oil changes every 10,000 km with 5W-40, 16 spark plugs every 60,000–80,000 km — then 400,000 km is realistic.
- !! Vibration Damper/Pulley — Rubber Hardens from 170,000 km
The rubber damper in the crankshaft pulley hardens with age and can eat into the sump — catastrophic consequential damage. Preventive replacement every 150,000 km strongly recommended.
Symptoms: Unusual vibrations at idle, in worst case metallic scraping from below. Often no prior warning — sudden failure. - !! Rear Crankshaft Seal Leaking from 150,000 km
The rear crankshaft seal is leaking on virtually all M113 engines above 150,000 km. Gearbox removal required — 600–900 EUR workshop costs. If oil creeps into the torque converter it becomes expensive.
Symptoms: Oil drops or oil film visible at the engine-gearbox interface, oil loss without any other apparent leak on the engine. - !! Engine Mounts Worn Prematurely from 90,000 km
Engine mounts can fail before 100,000 km. Practical test: finger between the stabiliser bar and front sump — no clearance means the mount is dead. Not visually checkable without removal.
Symptoms: Vibrations in interior especially at idle, dull rumbling on acceleration, in worst case contact between engine and bodywork.
+ 7 more engine weaknesses + vehicle weaknesses
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| Body rust from US manufacture The US-built W163 received insufficient corrosion protection from the factory. Boot lid, sills, wheel arches and bonnet are particularly susceptible. Symptoms: Rust bubbles under paint, perforations on boot lid and wheel arches, brown staining on sills from 120,000 km | High | |
| Rust on load-bearing frame members Ladder frame rusts heavily, particularly at the rear and at longitudinal member sections. Suspension mounting points can be so weakened by corrosion that the vehicle's roadworthiness is at risk. Symptoms: Visible surface rust on underbody, suspension noises from corroded bushes, MOT failure on load-bearing parts | High |
Test Reports
TÜV Report 2024
The first ML shows significant defect rates with age, particularly on suspension and corrosion.
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Explore more
Known Problems and Issues +
A total of 36 weaknesses have been documented for the Mercedes-Benz ML W163 (1997–2005) — 29 engine-related and 7 vehicle-related. One problem engine: OM612 (2.7L 5-Zyl Diesel). Typical issues affect Rust, Electronics, Brakes, Gearbox.
ML (OM612, 1999–2005) — Stay Away!: "Black Death" -- injector seal failure with tar formation, EGR cooler fails -- coolant in intake, Cylinder head crack -- coolant loss under load. Power: 163 PS.
ML (OM628, 2002–2005) — Be Careful: Timing chain and tensioner worn, Bi-turbo failure (right turbocharger preferentially), Coolant loss through cylinder head. Power: 250 PS.
ML (M112, 1997–2005) — Be Careful: Camshaft Adjuster Leaks Oil into Wiring Harness, Intake Manifold Vacuum Hose Breaks, Valve Cover Gasket and Front Cover Gasket Leaking. Power: 218 PS.
ML (M113, 1998–2001) — Be Careful: Vibration Damper/Pulley — Rubber Hardens, Rear Crankshaft Seal Leaking, Engine Mounts Worn Prematurely. Power: 272 PS.
ML (M113, 1999–2005) — Be Careful: Vibration Damper/Pulley — Rubber Hardens, Rear Crankshaft Seal Leaking, Engine Mounts Worn Prematurely. Power: 347 PS.
ML (M113, 2001–2005) — Be Careful: Vibration Damper/Pulley — Rubber Hardens, Rear Crankshaft Seal Leaking, Engine Mounts Worn Prematurely. Power: 292 PS.
ML (M112, 2002–2005) — Be Careful: Camshaft Adjuster Leaks Oil into Wiring Harness, Intake Manifold Vacuum Hose Breaks, Valve Cover Gasket and Front Cover Gasket Leaking. Power: 235 PS.
What to watch out for with the Mercedes-Benz ML? See the detailed listing of all engine and vehicle weaknesses in the sections above.
Frequently Asked Questions
What problems and weaknesses does the Mercedes-Benz ML W163 have? +
What should I look for when buying a used Mercedes-Benz ML W163? +
Which engine is recommended? +
Which Mercedes-Benz ML W163 engine is the most fun? +
Is the Mercedes-Benz ML W163 worth buying used? +
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Last updated: February 2026 · All information without guarantee