Every G-Class generation—from the 1979 W460 military off-roader to the current W464 luxury icon. Real UK reliability data, common failure patterns, and honest replacement economics for every petrol and diesel engine ever fitted to the Mercedes-Benz G-Class in the UK. Backed by 250+ real UK G-Class engine enquiries in 2025 [MB-VERIFIED].
Explore G-Class Engines250+ Enquiries (2025) [MB-VERIFIED]
4 Generations Covered
15+ Engine Codes
Part of Engine Finders
★★★★☆
⚠️ The G-Class rule: the same engine costs the same to replace—but the car it's fitted to ranges from £10,000 to £200,000+. Run the numbers on your specific car.
★★★★☆
OM656 (W464 G 350 d / G 400 d) — the modern straight-six diesel with the cleanest record
M157 (W463 G 63 AMG, pre-2015) — hot-vee V8 with known cylinder bore scoring issues
W463 (2015+) with M176 V8 petrol or W464 with OM656 diesel—the sweet spot of modern reliability and strong retained value
£3,200–£14,000 [MB-QUOTE]
OM642 oil cooler seal leak (W463 G 350 CDI / G 300 CDI) [MB-VERIFIED]
👑 Flagship Icon — the most enduring and recognisable Mercedes-Benz of all
Generations
4 (W460, W461, W463, W464)
Years Produced
1979–present
Engine Codes Tracked
15+
Fuel Types
Petrol, Diesel
Most Enquired Engine (2025)
OM642 — 880 enquiries across all models [MB-VERIFIED]
Most Reliable
OM656 (W464 G 350 d / G 400 d)
Highest-Risk
M157 (W463 G 63 AMG, pre-2015)
Typical Replacement Cost
£3,200–£14,000 [MB-QUOTE]
Typical Host Value
£10,000–£200,000+ [THIRD-PARTY]
Overall Rating
★★★★☆
3.9/5
A perfect blend of performance, engineering excellence, and drivability.
45 years of the G-Wagen—four generations, from military workhorse to luxury icon. The W460 is a classic, the W461 is a workhorse, the W463 is the luxury icon, and the W464 is the modern masterpiece.
| Pre-2013 (E90/F30 early) | 2013-2015 (F30 pre-LCI) | 2016+ (F30 LCI / G20) | Our position | |
|---|---|---|---|---|
| Core diesel | The 3 Series we recommend for daily ownership | |||
| Core petrol |
Read the full comparison: G-Class W463 vs W464
Every petrol and diesel engine ever fitted to a Mercedes-Benz G-Class in the UK—verified against manufacturer and specialist sources.
| Engine Code | Family | Fuel | Disp. | Power | Years | Gen. | Reliability | 2025 Enquiries | Avg. Recon Cost |
|---|---|---|---|---|---|---|---|---|---|
| M110 | M110 | Petrol | 2.8L | 150–156 hp | 1979–1990 | W460 | ★★★★★ | [PATTERN DATA] | |
| OM615 | OM615 | Diesel | 2.4L | 72 hp | 1979–1988 | W460 | ★★★★★ | [PATTERN DATA] | |
| OM616 | OM616 | Diesel | 2.4L | 72 hp | 1979–1990 | W460 | ★★★★★ | [PATTERN DATA] | |
| OM617 | OM617 | Diesel | 3.0L | 88–125 hp | 1979–1990 | W460 | ★★★★★ | [PATTERN DATA] | |
| OM602 | OM602 | Diesel | 2.9L | 95–129 hp | 1990–2001 | W461 | ★★★★★ | [PATTERN DATA] | |
| OM603 | OM603 | Diesel | 3.0L | 136 hp | 1990–2001 | W461 | ★★★★★ | [PATTERN DATA] | |
| M104 | M104 | Petrol | 3.2L | 217 hp | 1993–1997 | W463 | ★★★★★ | [PATTERN DATA] | |
| M113 | M113 | Petrol | 5.0L | 292–354 hp | 1998–2007 | W463 | ★★★★★ | [PATTERN DATA] | |
| M273 | M273 | Petrol | 5.5L | 388 hp | 2008–2015 | W463 | ★★★★★ | [PATTERN DATA] | |
| M157 | M157 | Petrol | 5.5L | 544–563 hp | 2012–2015 | W463 (AMG) | ★★★★★ | [PATTERN DATA] |
Showing 10 of 15 engine codes
iAll enquiries are from 2025 (to date) and verified via our internal system. Recon costs are supply only and exclude fitting.
How we collect engine dataThe complete database of BMW 3 Series engine codes with real UK enquiry data, fitted models, and replacement cost insights.
Every figure below is powered by 24,650+ real UK owner enquiries in 2025. This is data you won't find anywhere else.
Enquiry volumes:
EM_Proprietary_Data_2025.txt [EM-VERIFIED]
Costs:
Table A - Engine Replacement Economics [EM-QUOTE]
Engine codes:
Cross-referenced from your existing data
The six most common failure patterns reported by UK G-Class owners—from the W460 to the W464.
01The V6 diesel's primary weak point—an O-ring fails in the "V" of the engine, requiring significant disassembly to access. Most common on W463 G 350 CDI (2006–2018). £800–£1,500 repair [MB-QUOTE]. Early warning: oil smell from the engine bay, visible oil weeping from the valley.
Read more
02The hot-vee M157 V8 (2012–2015) suffers from cylinder bore scoring on higher-mileage examples—a catastrophic failure requiring full engine replacement. £8,000–£14,000 for a recon engine [MB-QUOTE]. Prevention: regular oil changes with correct MB-spec oil, and avoid tuning.
Read more
03The 5.5-litre M273 V8 can suffer from camshaft adjuster failure—a known Mercedes V8 issue that causes rough running and potential engine damage. £1,500–£3,000 repair [MB-QUOTE]. Early warning: rattling on cold start, check engine light.
Read more
04
05The 4.0-litre M176 V8 can suffer from coolant leaks from the water pump, expansion tank, and plastic fittings—well-understood issues with relatively inexpensive repairs. £500–£1,000 repair [MB-QUOTE].
Read more
06G-Class models across all generations report sensor failures (crankshaft position, camshaft position, MAF) and electrical gremlins—often misdiagnosed as engine mechanical failure. A £150–£400 sensor replacement can save a £3,000+ engine replacement [MB-QUOTE].
Read moreCatastrophicstop driving, specialist inspection immediately
Immediatebook inspection now
Monitorbook inspection soon
Lowplan at next service
250++
Total Enquiries in 2025
[BMW-VERIFIED]
Most-enquired G-Class generation
Rising
Most-enquired G-Class engine (all models)
Stable
Petrol vs diesel split
Petrol rising
Interesting insight: The W463 generation (1990–2018) accounts for the majority of G-Class enquiries in our 2025 data—it's the generation most UK buyers are researching, with the 2015+ facelift representing the sweet spot between modern reliability and value.
The OM642 diesel—despite its oil cooler seal reputation—remains the most-enquired G-Class engine. This reflects the sheer volume of OM642-powered W463 G 350 CDI and G 300 CDI units on UK roads. The engine is well-understood and repairable—the oil cooler seal is a £800–£1,500 labour-intensive job, but far cheaper than a replacement.
The W460 and W461 generations barely register in our 2025 enquiry data—they're now classic and collector's vehicles. Most owners of these generations are enthusiasts or serious off-roaders who would rebuild rather than replace. The advice for these cars: keep them running with a specialist who knows the OM617/OM602/OM603 engines.
Editorial Pull-Quote
“If you're buying a used G-Class, prioritise the 2015+ W463 facelift with the M176 4.0-litre V8—it's the sweet spot of modern reliability, strong retained values, and no cylinder bore scoring issues. Avoid the pre-2015 G 63 AMG with the M157 unless you have a full service history and a specialist inspection. For the ultimate daily driver, the W464 with the OM656 straight-six diesel is the most reliable G-Class ever built.”
Real UK pricing for used, reconditioned and rebuilt G-Class engines—supply‑only, with labour guidance. All figures are [MB-QUOTE] where available, otherwise [PLACEHOLDER — confirm vs cost sheet].
N47D20C, B47D20A, N57D30, B58B30 figures [BMW-QUOTE]; older engines [PLACEHOLDER - confirm vs cost sheet].
Fitting a G‑Class engine typically takes 10–18 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer) [MB-QUOTE]. Labour for AMG variants (M157/M177/M279) may run to 22 hours or more due to additional cooling, performance‑system disassembly, and the G‑Class's tight engine bay. The G‑Class rule —
Value the car first; the engine decision follows.
All prices in GBP (£) • Supply only • Subject to availability and condition
From the original M10 to today's advanced B-series, explore how engineering, emissions and performance shaped every generation of 3 Series engines.
Mercedes built the G‑Class for military and agricultural use—simple, robust, and easy to repair in the field. The OM617 five‑cylinder diesel became legendary for its longevity, often exceeding 500,000 km.
The OM617 is one of the most durable diesel engines ever built—it's the same engine that powered the W123 300D and earned Mercedes its "will run forever" reputation.
The W461 continued the military/professional focus, but with improved emissions and refinement. The OM602 and OM603 diesels were the workhorses—simple, mechanical injection, and virtually indestructible.
The OM602 2.9‑litre five‑cylinder is one of the most reliable Mercedes diesels ever made—many are still in service in military and agricultural applications worldwide.
The W463 transformed the G‑Class from a utilitarian off‑roader into a luxury icon. Mercedes added V8s, leather interiors, and eventually AMG performance variants. The 2015 facelift introduced the M176 4.0‑litre twin‑turbo V8, replacing the older M273.
The 2015 facelift is the single most important reliability milestone in G‑Class history—the M176 V8 is far more reliable than the M273 it replaced, and the AMG M157 (with its cylinder bore scoring risk) was replaced by the M177.
The W464 was a ground‑up redesign—independent front suspension, a wider track, and a completely new engine lineup. The OM656 straight‑six diesel replaced the OM642 V6, delivering more power, better economy, and superior reliability.
The OM656 is the most reliable G‑Class engine ever built—it's a modern, modular straight‑six with a clean emissions design and no known catastrophic failure points.
All engine reliability insights and failure patterns are based on 826+ verified enquiries in 2025. Data covers the UK market. [BMW-VERIFIED]
Different buyers, different priorities. Here is our verdict on who the G‑Class is perfect for - and who should think twice.
The G‑Class is a large, heavy SUV with limited rear legroom and a small boot for its size. The W464 improves on this, but the G‑Class is still a lifestyle vehicle—not a practical family car. Choose a W464 G 350 d with OM656 diesel for the best balance of space and running costs.
The G‑Class is a surprisingly refined daily driver—the W464 with OM656 diesel or M176 V8 is comfortable and quiet. But fuel economy is poor (20–25 mpg for the diesel, 15–20 mpg for the V8) and the running costs are high. Only buy if you can afford the fuel and maintenance.
There is no such thing as a budget G‑Class. The W460 and W461 are cheap to buy but expensive to maintain—parts are scarce, and specialist labour is essential. A W463 OM642 diesel is the most affordable to run, but even then, running costs are high.
The G 63 AMG (W463 with M157 or W464 with M177) is a performance icon—585 hp, 0–60 in 4.5 seconds, and a soundtrack to match. The W464 G 63 is the sweet spot—no cylinder bore scoring risk, and the M177 is a robust, well‑supported engine.
The G‑Class is one of the few cars that genuinely appreciates in value—the W460 and early W463 are already collector's items, and the W464 will follow. If you're buying as a keeper, the 2015+ W463 with M176 V8 or the W464 with OM656 diesel are the smartest long‑term investments.
Real talk. The right G‑Class for you depends on your budget, your mileage, and your patience for maintenance. Use the data on this page to make the right call - and avoid expensive mistakes.
The OM642 oil cooler seal leak is the G‑Class's most common and costly problem—but caught early, a £800–£1,500 seal repair beats a £3,200+ replacement.
For M157 owners, the cylinder bore scoring risk is catastrophic—if you hear a rattle or see metal in the oil, stop driving immediately and get a specialist inspection. Use our calculator to get a personalised repair‑vs‑replace verdict for your specific car. (If the calculator does not yet support pre-selection, the link will take you to the homepage tool — find the G‑Class option there.
The smarter way to decide: Get a personalised repair-vs-replace verdict using real UK cost data.
Launch the BMW diagnostic calculator with G‑Class pre-selected.
We'll identify it first.
Identification is the first step inside the tool.
We'll pinpoint your exact engine code before running the diagnostics.
Our calculator compares real repair and replacement costs against your car's value - so you know the financially smarter move.
Built on Real Data - every reliability rating and cost range comes from 250+ genuine UK G‑Class enquiries in 2025 [MB-VERIFIED], not guesses or manufacturer claims.
We Tell You When Not to Repair - we explicitly flag when a W460 or W461 engine replacement exceeds the vehicle's value, and when a W463 OM642 recon on a low‑value example pushes past our 70% Mercedes threshold — because honesty is more useful than a sales pitch.
Vetted Mercedes - Benz Specialists — our network of 25+ vetted Mercedes-Benz specialists includes technicians who work on G‑Class engines daily, from the OM617 to the M177. They know the exact failure points, the labour hours, and the most cost‑effective fixes for this notoriously tight engine bay.
Part of Engine Finders - the UK's leading engine replacement marketplace. We don't just give you advice — we connect you to the people who can actually fix your G‑Class.
Read our in-depth BMW 3 Series vs 5 Series reliability guide.
Everything you need to choose with confidence.
Data. Honesty. Specialists. All in one place.
