Mercedes Benz G Class G 350 d Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz G Class G 350 d engine specialists. Compare prices on reconditioned, rebuilt and used OM642 diesel engines - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From £4,800 to £7,500
Used from £2,500 · Reconditioned from £4,200 · Common codes: OM642.887, OM642.886, OM642 LS
From £2,500
Tested, bare/short engine
From £4,200
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 G Class G 350 d Replacement Engineto Finding the Best Mercedes Benz G Class G 350 d Replacement Engine
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Variant HistoryMercedes Benz G Class G 350 d - Engine History & Specs at a Glance
The Mercedes Benz G 350 d arrived in 2015 as the facelifted W463 generation's updated diesel flagship, replacing the G 350 CDI with a more powerful iteration of the OM642 V6 diesel - and later transitioned to the W464 generation with the same engine before being phased out in favour of the OM656 inline-six in the G 400 d.
Variant HistoryMercedes Benz G Class G 350 d - Engine History & Specs at a Glance
The Mercedes Benz G 350 d arrived in 2015 as the facelifted W463 generation's updated diesel flagship, replacing the G 350 CDI with a more powerful iteration of the OM642 V6 diesel - and later transitioned to the W464 generation with the same engine before being phased out in favour of the OM656 inline-six in the G 400 d.
Mercedes Benz G Class G 350 d
Fuel TypeDiesel
Engine Size3.0L (2,987cc)
Power Output245hp @ 3,600rpmEngine History Timeline
G 350 d introduced with W463 facelift OM642.887 3.0L V6 diesel, 245hp, Euro 6 emissions compliance
2018 - W463 G 350 d production 7G-TRONIC PLUS automatic transmission, 600Nm torque
W464 all-new G-Class launched G 350 d continues with OM642 V6 diesel in the new platform
2023 - W464 G 350 d production continues with OM642 later phased out as G 400 d (OM656 inline-six) became the primary diesel offering
Key Specs Snapshot
Fuel TypeDieselEngine Size3.0L (2,987cc)Power Output245hp @ 3,600rpmTorque600Nm @ 1,600-2,400rpmYears Produced2015-2023Every OM642 engine fitted to the Mercedes Benz G Class G 350 d is covered below, with UK rebuilt pricing and known failure points from real owner experience.
Mercedes Benz G Class G 350 d Engine Codes - Specifications & Replacement CostMercedes Benz G Class G 350 d Engine Codes - Specifications & Replacement Cost
3.0L V6 Diesel (2015-2018)
Power Output245 hp @ 3,600rpmTorque600Nm @ 1,600-2,400rpmYears Fitted2015-2018
Compatible Trim Levels
- G 350 d (W463)
- G 350 d Professional
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£2,500-£4,000
Reconditioned
Addressed known issues, tested
£4,200-£6,000
Rebuilt
Full teardown, upgraded internals
£4,800-£7,500
Common Failure
The OM642.887 shares the V6 diesel family's well-documented oil cooler seal failure - the rubber seals harden and shrink due to heat cycling, allowing oil to mix with coolant and external oil leaks to form at the V-angle of the engine. This affects approximately 80% of OM642 engines over 60,000 miles.
The Mercedes Benz G Class G 350 d relies on the OM642 V6 diesel - a generally robust engine that has developed a well-documented reputation for specific failures. The oil cooler seal issue dominates replacement demand, while EGR cooler and turbocharger-related problems also drive repair enquiries. Every rebuilt engine supplied through EnginesMarket includes upgraded components designed to address the original failure point - plus a minimum 12-month unlimited mileage warranty. Below we break down the most common G 350 d engine failures, what they cost to fix, and when replacement is the smarter financial decision.
Why the G 350 d Leaks Oil Excessively
Affected Vehicles
Mercedes Benz G Class G 350 d (OM642.887, OM642 LS, 2015-2023)
Typical Failure Mileage
60,000 - 90,000 miles
Root Cause
The factory rubber oil cooler seals harden and shrink due to heat cycling, allowing oil to mix with coolant and external oil leaks to form at the V-angle of the engine. Mercedes Service Bulletin LI18.30-P-055434 addresses this known issue.
Why It Happens
The factory rubber oil cooler seals harden and shrink due to heat cycling, allowing oil to mix with coolant and external oil leaks to form at the V-angle of the engine. Mercedes Service Bulletin LI18.30-P-055434 addresses this known issue.
Dealer (parts + labour)
£1,800-£2,500
Specialist (parts + labour)
£900-£1,400
What it involves
Replace oil cooler seals (revised parts), flush cooling system, new oil and filter
Suitability
60k-80k miles if using revised Viton seals
1 - 2 daysDealer (parts + labour)
£2,500-£3,500
Specialist (parts + labour)
£1,400-£2,000
What it involves
Replace complete oil cooler unit with revised seals, coolant flush, thermostat inspection
Suitability
80k-100k miles; recommended if cooler shows corrosion
1 - 2 daysDealer (parts + labour)
£8,000-£12,000
Specialist (parts + labour)
£4,800-£7,500
What it involves
Supply & fit rebuilt OM642 with upgraded seals, new oil pump chain, turbo inspected
Suitability
100k+ miles with extended warranty cover
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 - Seal Replacement Minor | £1,800-£2,500 | £900-£1,400 | Replace oil cooler seals (revised parts), flush cooling system, new oil and filter | 60k-80k miles if using revised Viton seals | 1 - 2 days |
 Intermediate - Oil Cooler & Seal Assembly Best Value | £2,500-£3,500 | £1,400-£2,000 | Replace complete oil cooler unit with revised seals, coolant flush, thermostat inspection | 80k-100k miles; recommended if cooler shows corrosion | 1 - 2 days |
Full Replacement - Rebuilt Engine Best Value | £8,000-£12,000 | £4,800-£7,500 | Supply & fit rebuilt OM642 with upgraded seals, new oil pump chain, turbo inspected | 100k+ miles with extended warranty cover | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical G 350 d is worth £25,000-£60,000 depending on age, mileage and condition - the full replacement cost of £4,800-£7,500 is modest relative to vehicle value, making a specialist rebuilt engine excellent value. For vehicles worth under £10,000 (high-mileage examples), evaluate repair options first.
Our Recommendation
Our Recommendation
If caught early with only external weeping, the seal-only specialist fix at £900-£1,400 is excellent value and should last 60k+ miles with revised seals. However, if the leak has caused coolant contamination or the engine has overheated, we recommend the full rebuilt route - contaminated oil galleries often cause turbo or bearing failure within 10k-15k miles of a partial repair.
Don't Let Engine Failure Write Off Your Mercedes Benz G Class G 350 d
A failed engine doesn't have to mean the end of your G 350 d. Whether you're dealing with an OM642 oil cooler seal leak, EGR cooler failure, or turbocharger issues, EnginesMarket makes it simple to compare prices from trusted UK Mercedes Benz G Class specialists. Every rebuilt engine in our network includes upgraded components designed to address the original failure point, a minimum 12-month unlimited mileage warranty, and nationwide delivery with supply & fit options available.
Compare rebuilt OM642 Mercedes Benz G Class G 350 d engine prices
12-Month Minimum
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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 Benz G Class G 350 d. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
Mercedes Benz G Class G 350 d Engine ReplacementFrequently Asked Questions
Question 1How much does it cost to replace a Mercedes G Class G 350 d engine in the UK-
A Mercedes G Class G 350 d engine replacement typically costs between £4,800 and £7,500 depending on condition type and whether fitting is included. Rebuilt OM642 units range from £4,800 to £7,500 supply only.
- Rebuilt OM642.887 (G 350 d): £4,800-£7,500 supply only
- Used engines from breakers: £2,500-£4,000 but higher risk
- Reconditioned units: £4,200-£6,000
- Labour for supply & fit adds £800-£1,500 to any engine price
Question 2What are the signs of OM642 oil cooler seal failure in a G 350 d-
The OM642's oil cooler seals typically fail between 60,000-90,000 miles, with tell-tale signs including oil spots under the vehicle and coolant contamination.
- Oil drips on the ground beneath the engine bay, particularly towards the rear
- Oil in the coolant expansion tank (may appear as a milky or oily film)
- External oil weeping from the V-angle of the engine
- Low oil level warnings between services
Question 3Is the OM642 engine in the G 350 d reliable-
The OM642 is generally robust but has a known weak point - the oil cooler seals fail on a significant proportion of units after 60,000 miles. Address this preventatively and the engine easily exceeds 150,000 miles.
- Oil cooler seal failure is the most common G 350 d issue
- Post-2015 engines have improved single-row timing chains that are more durable
- Regular oil changes with correct 229.51/229.52 spec oil are critical
- With preventative maintenance, 200,000+ miles is realistic
Question 4Should I repair or replace my G 350 d engine-
Repair if the failure is isolated (e.g., oil cooler seals, EGR cooler, turbo VNT cleaning). Replace if there's bottom end damage, bore scoring, or multiple major failures.
- Oil cooler seal replacement at specialist: £900-£1,400 - excellent value if caught early
- EGR cooler replacement: £700-£1,100 - sensible repair for 80k+ mile cars
- Full OM642 rebuild: £4,800-£7,500 - for catastrophic failure or 150k+ miles
- Given G 350 d values (£25,000-£60,000), a rebuilt engine is typically good value
Question 5How do I know which engine code my G 350 d has-
Check your vehicle log book (V5C) for the engine number, which includes the engine code prefix (e.g., OM642).
- V5C log book shows full engine number with code prefix
- Engine code stamped on cylinder block (visible from under vehicle)
- G 350 d (W463, 2015-2018): OM642.887
- G 350 d (W464, 2018-2023): OM642 LS or OM642.887
- Service history documents list engine type
Question 6Can I fit a used G 350 d engine myself-
We strongly advise against DIY fitting on a G 350 d. The complex 4MATIC system, gearbox alignment, and ECU coding requirements demand specialist equipment and expertise.
- 4MATIC transfer case alignment requires specialist jigs
- ECU coding and immobiliser synchronisation needed
- Engine and gearbox must be separated correctly
- Specialist supply & fit costs £800-£1,500 - worth every penny
Question 7What warranty comes with a reconditioned G 350 d engine-
Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty, with many specialists offering 24-month coverage on OM642 rebuilds. This includes parts and labour for any manufacturing defect or installation error.
- 12-month unlimited mileage is the minimum standard
- OM642 rebuilds often include 24-month warranty
- All warranties cover parts, labour, and MOT compliance
- Extended warranties available at point of purchase
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