Mercedes Benz G Class G 350 / G 500 (Older Petrol) Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz G Class G 350 and G 500 petrol engine specialists. Compare prices on reconditioned, rebuilt and used M112 V6 and M113 V8 engines - supply & fit available nationwide.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From £3,800 to £6,800
Used from £1,500 · Reconditioned from £3,200 · Common codes: M112.945, M113.962
From £1,500
Tested, bare/short engine
From £3,200
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 / G 500 (Older Petrol) Replacement Engineto Finding the Best Mercedes Benz G Class G 350 / G 500 (Older Petrol) Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryMercedes Benz G Class G 350 / G 500 (Older Petrol) - Engine History & Specs at a Glance
The Mercedes Benz G Class G 350 and G 500 petrol models represent the classic V6 and V8-powered W463 generation that defined the G-Class as a luxury off-roader throughout the 1990s and 2000s - from the 3.2-litre M112 V6 in the G 320 through to the 5.0-litre M113 V8 in the G 500.
Variant HistoryMercedes Benz G Class G 350 / G 500 (Older Petrol) - Engine History & Specs at a Glance
The Mercedes Benz G Class G 350 and G 500 petrol models represent the classic V6 and V8-powered W463 generation that defined the G-Class as a luxury off-roader throughout the 1990s and 2000s - from the 3.2-litre M112 V6 in the G 320 through to the 5.0-litre M113 V8 in the G 500.
Mercedes Benz G Class G 350 / G 500 (Older Petrol)
Fuel TypePetrol
Engine Size Range3.2L - 5.0L
Power Output Range215-296hp across the G 320 and G 500Engine History Timeline
500 GE launched as limited-edition V8 (446 units worldwide) M117 5.0L V8, 240hp
G 500 launched with M113 5.0L V8 296hp, 5-speed automatic
2005 - G 320 offered with M112 3.2L V6 215hp, 5-speed automatic
2012 - G 55 AMG introduced alongside G 500 M113K supercharged 5.4L V8 (covered on dedicated AMG page)
Key Specs Snapshot
Fuel TypePetrolEngine Size Range3.2L - 5.0LPower Output Range215-296hp across the G 320 and G 500Years Produced1998-2008 (G 500), 1998-2005 (G 320)Every petrol engine fitted to the Mercedes Benz G Class G 350 and G 500 range is covered below, with UK rebuilt pricing and known failure points from real owner experience.
Mercedes Benz G Class G 350 / G 500 (Older Petrol) Engine Codes - Specifications & Replacement CostMercedes Benz G Class G 350 / G 500 (Older Petrol) Engine Codes - Specifications & Replacement Cost
3.2L V6 Petrol (1998-2005)
Power Output215 hpYears Fitted1998-2005
Compatible Trim Levels
- G 320 (W463)
Mercedes Benz G Class G 350 / G 500 (Older Petrol) engine replacement
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£1,200-£2,800
Reconditioned
Addressed known issues, tested
£2,800-£4,200
Rebuilt
Full teardown, upgraded internals
£3,800-£6,000
Common Failure
The M112 is considered one of Mercedes' most reliable V6 engines. However, valve cover gaskets and breather cover seals can develop oil leaks as the engine ages. The harmonic balancer (crankshaft pulley) has also been subject to failure reports on some M112-equipped vehicles.
The Mercedes Benz G Class G 320 and G 500 rely on the M112 V6 and M113 V8 engine families - both considered among Mercedes' most reliable petrol engines. However, age and mileage bring well-documented issues: oil leaks from valve cover gaskets, timing chain tensioner wear on higher-mileage examples, and harmonic balancer failures. 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 Class petrol engine failures, what they cost to fix, and when replacement is the smarter financial decision.
Why G Class Petrol Engines Drip Oil
Affected Vehicles
Mercedes Benz G Class G 320 (M112.945, 1998-2005) and G 500 (M113.962, 1998-2008)
Typical Failure Mileage
80,000 - 150,000 miles
Root Cause
The valve cover gaskets and breather cover seals harden and crack due to repeated hot/cold engine cycles, allowing oil to weep onto the exhaust manifolds. This is a common problem on both M112 and M113 engines as they age.
Why It Happens
The valve cover gaskets and breather cover seals harden and crack due to repeated hot/cold engine cycles, allowing oil to weep onto the exhaust manifolds. This is a common problem on both M112 and M113 engines as they age.
Dealer (parts + labour)
£600-£900
Specialist (parts + labour)
£300-£500
What it involves
Replace valve cover gaskets, breather cover seals, new gaskets and RTV sealant
Suitability
80k-150k miles; excellent preventative maintenance
1 - 2 daysDealer (parts + labour)
£1,200-£1,800
Specialist (parts + labour)
£700-£1,100
What it involves
Replace valve cover gaskets, breather covers, PCV system, oil filter housing gasket
Suitability
100k+ miles; recommended if multiple leaks present
1 - 2 daysDealer (parts + labour)
£6,000-£9,000
Specialist (parts + labour)
£3,800-£6,800
What it involves
Supply & fit rebuilt M112 or M113 with new gaskets, seals, and upgraded components
Suitability
Full long-block warranty; for catastrophic failure or 200k+ miles
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 - Valve Cover Gasket Replacement (Both Sides) Minor | £600-£900 | £300-£500 | Replace valve cover gaskets, breather cover seals, new gaskets and RTV sealant | 80k-150k miles; excellent preventative maintenance | 1 - 2 days |
 Intermediate - Full Top-End Reseal Best Value | £1,200-£1,800 | £700-£1,100 | Replace valve cover gaskets, breather covers, PCV system, oil filter housing gasket | 100k+ miles; recommended if multiple leaks present | 1 - 2 days |
Full Replacement - Rebuilt Engine Best Value | £6,000-£9,000 | £3,800-£6,800 | Supply & fit rebuilt M112 or M113 with new gaskets, seals, and upgraded components | Full long-block warranty; for catastrophic failure or 200k+ miles | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical G 320 is worth £8,000-£18,000 depending on condition, while a G 500 is worth £12,000-£30,000【INDUSTRY ESTIMATE】. For the G 500, the full replacement cost of £4,200-£6,800 is modest relative to vehicle value. For a G 320, evaluate repair vs replacement based on overall condition.
Our Recommendation
Our Recommendation
Oil leaks on M112 and M113 engines are rarely urgent but should not be ignored. The specialist valve cover gasket replacement at £300-£500 is excellent value and should last 80k+ miles. If you're already addressing one leak, consider doing the full top-end reseal - the labour overlaps significantly and the additional parts cost is modest.
Don't Let Engine Failure Write Off Your Mercedes Benz G Class G 350 or G 500
A failed engine doesn't have to mean the end of your classic G-Class petrol. Whether you're dealing with an M112 oil leak, M113 timing chain tensioner wear, or harmonic balancer failure, 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 M112 or M113 Mercedes Benz G Class petrol 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 Benz G Class G 350 or G 500. 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 / G 500 (Older Petrol) Engine ReplacementFrequently Asked Questions
Question 1How much does it cost to replace a Mercedes G Class G 500 engine in the UK-
A Mercedes G Class G 500 engine replacement typically costs between £4,200 and £6,800 depending on condition type and whether fitting is included. M113 V8 units range from £4,200 to £6,800 supply only. M112 V6 units (G 320) range from £3,800 to £6,000.
- Rebuilt M113 (G 500): £4,200-£6,800 supply only
- Rebuilt M112 (G 320): £3,800-£6,000 supply only
- Used engines from breakers: £1,200-£3,500 but higher risk
- Labour for supply & fit adds £800-£1,500 to any engine price
Question 2Is the M113 V8 engine in the G 500 reliable-
The M113 is regarded as one of Mercedes' greatest achievements - durable, simple in design, and delivering impressive longevity when properly maintained. However, age brings some well-documented issues.
- Oil leaks from valve cover gaskets and breather covers are common
- Timing chain tensioner wear causes cold-start rattle
- Harmonic balancer failure can occur on higher-mileage examples
- With preventative maintenance, 200,000+ miles is realistic
Question 3What are the signs of M113 timing chain tensioner wear in a G 500-
The M113's hydraulic timing chain tensioner typically shows warning signs before complete failure - a rattling noise on cold start is the most common symptom.
- Rattling or clanking noise from the front of the engine on cold startup
- Noise that lasts more than 2 seconds indicates significant chain slack
- Rattle that disappears within 1 second may be normal hydraulic bleed-down
- If ignored, the chain can skip teeth and cause catastrophic engine damage
Question 4Should I repair or replace my G 320 or G 500 engine-
Repair if the failure is isolated (e.g., valve cover gaskets, timing chain tensioner, harmonic balancer). Replace if there's bottom end damage, bore scoring, or multiple major failures.
- Valve cover gasket replacement at specialist: £300-£500 - excellent value
- Timing chain tensioner replacement: £250-£400 - do this at first sign of rattle
- Full M113 rebuild: £4,200-£6,800 - for catastrophic failure or 200k+ miles
- Given G 500 values (£12,000-£30,000), a rebuilt engine is typically good value
Question 5How do I know which engine code my G 320 or G 500 has-
Check your vehicle log book (V5C) for the engine number, which includes the engine code prefix (e.g., M112, M113).
- V5C log book shows full engine number with code prefix
- Engine code stamped on cylinder block (visible from under vehicle)
- G 320 (1998-2005): M112.945 (3.2L V6)
- G 500 (1998-2008): M113.962 (5.0L V8)
- Service history documents list engine type
Question 6Can I fit a used G 320 or G 500 engine myself-
We strongly advise against DIY fitting on a G Class petrol. The complex 4MATIC system, gearbox alignment, and ECU coding requirements demand specialist equipment and expertise.
- 4MATIC transfer case alignment requires specialist knowledge
- 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 320 or G 500 engine-
Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty, with many specialists offering 24-month coverage on M113 rebuilds. This includes parts and labour for any manufacturing defect or installation error.
- 12-month unlimited mileage is the minimum standard
- M113 rebuilds often include 24-month warranty
- All warranties cover parts, labour, and MOT compliance
- Extended warranties available at point of purchase
Why Choose UsCompare Mercedes Benz G Class G 350 / G 500 PetrolEngine PricesToday
100+ G Class petrol engines supplied through our network
12-Month Warranty on every rebuilt G 320 and G 500 engine
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