Mercedes Benz M Class 230/350 Petrol Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz M Class 230 and 350 petrol engine specialists. Compare prices on reconditioned, rebuilt and used engines for the 2.3-litre inline-four and the 3.7-litre V6 - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
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From £1,900 to £3,200
Used from £1,000 · Reconditioned from £1,900 · Common codes: M111.977, M112.970
From £1,000
Tested, bare/short engine
From £1,900
Rod bearings addressed, tested
From quote
Upgraded bearings, full teardown, revised valvetrain
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3 Simple Steps3 Simple Stepsto Finding the Best Mercedes Benz M Class 230/350 Petrol Replacement Engineto Finding the Best Mercedes Benz M Class 230/350 Petrol Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryMercedes Benz M Class 230/350 Petrol - Engine History & Specs at a Glance
The ML 230 launched with the W163 generation in 1997 as the entry-level petrol M Class, powered by the M111 2.3-litre inline-four producing 150hp - a robust, simple engine that established the M Class as a premium SUV contender. In 2002, the ML 350 joined the range with the M112 3.7-litre V6, delivering 235hp and representing a significant step up in refinement and power. These petrol variants offered a refined alternative to the diesel CDI models for owners prioritising smooth power delivery.
Variant HistoryMercedes Benz M Class 230/350 Petrol - Engine History & Specs at a Glance
The ML 230 launched with the W163 generation in 1997 as the entry-level petrol M Class, powered by the M111 2.3-litre inline-four producing 150hp - a robust, simple engine that established the M Class as a premium SUV contender. In 2002, the ML 350 joined the range with the M112 3.7-litre V6, delivering 235hp and representing a significant step up in refinement and power. These petrol variants offered a refined alternative to the diesel CDI models for owners prioritising smooth power delivery.
Mercedes Benz M Class 230/350 Petrol
Fuel TypePetrol (naturally aspirated)
Engine Size Range2.3L-3.7L (M111: 2,295cc; M112: 3,724cc)
Power Output Range150-235hp across the variant's historyEngine History Timeline
M111.977 2.3L inline-four petrol, 150hp @ 5,400rpm (ML 230, W163 launch)
2001 - ML 230 continues as entry-level petrol option
M112.970 3.7L V6 petrol, 235hp @ 5,750rpm (ML 350, W163)
End of W163 production; ML 230 and ML 350 replaced by W164 generation with M272 V6
Key Specs Snapshot
Fuel TypePetrol (naturally aspirated)Engine Size Range2.3L-3.7L (M111: 2,295cc; M112: 3,724cc)Power Output Range150-235hp across the variant's historyYears Produced1997-2005Every engine fitted to the Mercedes Benz M Class 230 and 350 petrol is covered below, with UK rebuilt pricing and known failure points - from M111 timing chain wear to M112 harmonic balancer separation.
Mercedes Benz M Class 230/350 Petrol Engine Codes - Specifications & Replacement CostMercedes Benz M Class 230/350 Petrol Engine Codes - Specifications & Replacement Cost
2.3L Inline-Four Petrol (1997-2001)
Power Output150 hp (110 kW) @ 5,400 rpmTorque220 Nm @ 3,700-4,800 rpmYears Fitted1997-2001Displacement2,295ccCylindersInline 4, DOHC, 16-valveEngine CodeM 111 E 23 / 111.977
Compatible Trim Levels
- ML 230
- ML 230 4MATIC
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£1,000-£1,600
Reconditioned
Addressed known issues, tested
£1,800-£2,400
Rebuilt
Full teardown, upgraded internals
£2,000-£2,800
Common Failure
Timing chain wear and tensioner fatigue - the M111's double roller chain can stretch over time, particularly on higher-mileage examples. Harmonic balancer rubber separation can also occur, causing engine vibration and potential accessory drive issues. Valve cover gasket oil seepage is common with age.
The M Class 230's M111 inline-four and the 350's M112 V6 are among Mercedes' most straightforward petrol engines - simple, robust, and capable of 150,000+ miles with proper maintenance. However, both have well-documented weak points that become more pronounced with age and mileage. The M111 suffers from timing chain wear and harmonic balancer issues, while the M112 is prone to harmonic balancer rubber separation and oil leaks. Every rebuilt engine supplied through EnginesMarket includes upgraded components addressing these original failure points, plus a minimum 12-month unlimited-mileage warranty.
The 2.3 Petrol's Age-Related Failures
Affected Vehicles
Mercedes M Class ML 230 (M111.977, 1997-2001)
Typical Failure Mileage
80,000-150,000 miles
Root Cause
The M111's double roller timing chain can stretch over time, particularly if oil change intervals have been extended. Harmonic balancer rubber separation can also occur with age, causing engine vibration and potential accessory drive failure.
Why It Happens
The M111's double roller timing chain can stretch over time, particularly if oil change intervals have been extended. Harmonic balancer rubber separation can also occur with age, causing engine vibration and potential accessory drive failure.
Dealer (parts + labour)
£400-£700
Specialist (parts + labour)
£250-£500
What it involves
Replace timing chain tensioner only
Suitability
Effective if caught early when rattle first appears
1 - 2 daysDealer (parts + labour)
£1,200-£1,800
Specialist (parts + labour)
£800-£1,200
What it involves
Replace timing chain, guides, tensioner, sprockets
Suitability
If chain rattle is present but no fault codes
1 - 2 daysDealer (parts + labour)
£400-£700
Specialist (parts + labour)
£250-£500
What it involves
Replace crankshaft harmonic balancer, inspect belt
Suitability
If vibration or rubber separation is evident
1 - 2 daysDealer (parts + labour)
£4,000-£5,500
Specialist (parts + labour)
£2,000-£2,800
What it involves
Supply & fit rebuilt M111 with new timing components and harmonic balancer, 12-month warranty
Suitability
If timing failure has caused valve damage
1 - 2 daysAll prices are indicative UK market ranges based on current UK specialist supplier data.| Repair Tier | Dealer (Parts + Labour) | Specialist (Parts + Labour) | What It Involves | Suitability | Estimated Time |
|---|---|---|---|---|---|
 Minor - Timing chain tensioner replacement Minor | £400-£700 | £250-£500 | Replace timing chain tensioner only | Effective if caught early when rattle first appears | 1 - 2 days |
 Intermediate - Full timing chain kit Best Value | £1,200-£1,800 | £800-£1,200 | Replace timing chain, guides, tensioner, sprockets | If chain rattle is present but no fault codes | 1 - 2 days |
Intermediate - Harmonic balancer replacement Best Value | £400-£700 | £250-£500 | Replace crankshaft harmonic balancer, inspect belt | If vibration or rubber separation is evident | 1 - 2 days |
Full Replacement - Rebuilt M111 engine Best Value | £4,000-£5,500 | £2,000-£2,800 | Supply & fit rebuilt M111 with new timing components and harmonic balancer, 12-month warranty | If timing failure has caused valve damage | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical 1997-2001 ML 230 is worth approximately £2,000-£6,000 depending on condition and mileage. These classic SUVs sit in a value band where repair decisions require careful consideration - a full engine replacement may approach or exceed the vehicle's value for higher-mileage or cosmetically challenged examples.
Our Recommendation
Our Recommendation
If your ML 230 exhibits timing chain rattle on cold start or noticeable engine vibration, have a specialist inspect the timing components and harmonic balancer immediately. The M111's timing chain replacement at a specialist is significantly cheaper than dealer rates. On an ML 230 worth £2,000-£6,000, preventative attention to these issues is always the better investment.
Don't Let Timing Chain Wear, Harmonic Balancer Issues, or Oil Leaks Write Off Your Mercedes ML 230 or 350 Petrol
Whether you're facing M111 timing chain wear on your ML 230 or M112 harmonic balancer issues on your ML 350, EnginesMarket makes it simple to compare quotes from trusted UK Mercedes petrol specialists. Every rebuilt engine in our network carries upgraded components addressing the original design weakness - new timing components, harmonic balancers, and gaskets - plus a minimum 12-month unlimited mileage warranty with nationwide delivery and supply & fit options. Don't pay main dealer premiums. Compare prices from independent Mercedes specialists who know these classic petrol engines inside out.
Compare rebuilt M111 Mercedes M Class 230 engine prices
12-Month Minimum
UK Specialists Vetted
Best Price GuidanceImportant Information
Important Information
"All prices are indicative UK market ranges based on historical quote data and repair requests from our network of engine specialists. Dealer pricing is estimated based on published main dealer labour rates and genuine OEM parts pricing. Specialist pricing reflects actual quote data from EnginesMarket's UK network. Actual costs vary depending on damage severity, vehicle condition, variant, and workshop location within the UK. Use our free comparison tool to get tailored quotes for your specific Mercedes M Class 230 or 350 petrol. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
Mercedes Benz M Class 230/350 Petrol Engine ReplacementFrequently Asked Questions
Question 1How much does a Mercedes ML 230 or 350 petrol engine replacement cost in the UK-
Short summary: A rebuilt M111 engine for the ML 230 costs £2,000-£2,800 supply-only; a rebuilt M112 V6 engine for the ML 350 costs £2,400-£3,200 supply-only. Fitting adds £800-£1,500 depending on complexity - both engines are relatively straightforward to work on.
- ML 230 (M111.977): rebuilt unit £2,000-£2,800; used engine from £1,000
- ML 350 (M112.970): rebuilt unit £2,400-£3,200; used engine from £1,200
- M111 timing chain kit (labour only): £800-£1,200 at specialist
- M112 harmonic balancer replacement: £350-£600 at specialist
Question 2What are the signs of harmonic balancer failure on a Mercedes ML 350-
Short summary: Engine vibration, belt noise, or visible rubber separation on the harmonic balancer are the classic warning signs on the M112 V6. The bonded rubber layer between the inner and outer sections can separate with age, causing the outer ring to slip and potentially damage accessory belts.
- Noticeable engine vibration at idle or under load
- Squealing or chirping noise from the front of the engine
- Visible cracks or rubber separation on the harmonic balancer
- If caught early, replacement costs £350-£600 at specialist
Question 3Is the Mercedes ML 230 or 350 petrol engine reliable-
Short summary: Both the M111 inline-four and the M112 V6 are among Mercedes' most straightforward and reliable petrol engines. With regular maintenance and proactive attention to known issues like timing chain wear and harmonic balancer separation, these engines routinely exceed 150,000 miles.
- M111 and M112 are fundamentally robust - 150k+ miles common
- M111 timing chain wear is the most frequent issue - £800-£1,200 specialist fix
- M112 harmonic balancer separation is a known weakness - £350-£600 specialist fix
- Regular oil changes with MB 229.5 spec oil extend engine life
Question 4How long do Mercedes ML 230 and 350 petrol engines last-
Short summary: Properly maintained M111 and M112 engines routinely reach 150,000-200,000 miles before major work is needed. These simple, robust petrol engines are known for their longevity when serviced regularly.
- M111 (230): 150,000-200,000 miles with regular servicing
- M112 (350): 150,000-200,000 miles with proper maintenance
- Harmonic balancer inspection recommended from 80,000 miles
- Regular oil changes every 10,000 miles are essential
Question 5Is it worth replacing the engine in my Mercedes ML 230 or 350 petrol-
Short summary: Yes, if the M Class is otherwise in good condition with no rust or major transmission faults. A rebuilt M111 costs £2,000-£2,800 - comparable to the value of a £2,000-£8,000 vehicle, making it a justifiable investment for well-maintained examples. For the ML 350, the higher value range (£3,000-£8,000) makes replacement even more viable.
- ML 230 values: £2,000-£6,000 depending on condition and mileage
- ML 350 values: £3,000-£8,000 - classic SUV values remain strong for well-maintained examples
- Rebuilt engine with upgraded components fixes original weak points
- Supply & fit typically £2,800-£4,700 depending on engine code
- New engine includes 12-month unlimited mileage warranty
Question 6What oil does my Mercedes ML 230 or 350 petrol need-
Short summary: Mercedes-Benz specifies MB 229.5 high-performance oil - typically 5W-30 or 5W-40 fully synthetic. The M111 requires approximately 5.5 litres; the M112 V6 requires approximately 6.5 litres.
- M111 (230): MB 229.5 5W-30 or 5W-40 - high-spec synthetic only
- M112 (350): MB 229.5 5W-30 or 5W-40 - 6.5L capacity
- Never use non-approved oil - can cause timing chain and hydraulic lifter issues
- Change every 10,000 miles or 12 months
Why Choose UsCompare Mercedes M Class 230/350 PetrolEngine PricesToday
500+ classic petrol engines supplied through our network
12-Month Warranty on every rebuilt ML 230 and 350 petrol engine
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supply & fit available for M111 and M112
Comparing quotes for your Mercedes ML 230 or 350 petrol is completely free, with no obligation and no pressure. Enter your registration above to get tailored quotes from UK Mercedes petrol specialists who understand the M111 inline-four and M112 V6 engines inside out. Whether you need a used engine, a reconditioned unit, or a full rebuilt engine with upgraded timing components, harmonic balancers, and gaskets, we'll connect you with the right specialist for your exact M Class - with a minimum 12-month warranty on every engine supplied.
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