Mercedes Benz M Class 230/350 Petrol Engine Replacement Compare Prices & Get Quotes

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

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

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

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

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

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