How much does a Mercedes‑AMG G63 engine replacement cost in the UK?

A reconditioned G63 engine (M157 or M177) typically costs £6,200–£9,000 supply only depending on generation. A replacement M157.984 engine costs on average £7,908 in good condition. Reconditioned M157 engines start from around £6,200. Fitting adds £1,500–£2,500. Labour costs are higher than for conventional engines due to the hot‑vee design and the G‑Class's complex chassis. Use our calculator for a figure specific to your vehicle.

Is the Mercedes‑AMG G63 engine reliable?

The M157 and M177 are engineering masterpieces, but they are high‑stress, high‑temperature engines with well‑documented weaknesses. The M177 suffers from rear main seal and oil separator failure – 'one of the most frequent and expensive problems'. Oil leaks, turbocharger issues, and cylinder scoring are also concerns. With rigorous maintenance (oil changes every 8,000‑10,000 miles), these engines can be durable – but repairs are expensive. As one specialist noted, 'Issues are possible but not probable. It's likely that the resulting repairs be more expensive than a less expensive engine in a less expensive car'.

What are the common problems with the Mercedes‑AMG G63?

On the M177 (W464, 2019‑present), the most common issues are rear main seal and oil separator failure (causing oil leaks), turbocharger wear (reduced boost, lag), oil leaks from turbo inlet and oil cooler seals, and cylinder scoring (misfire, loss of compression). On the M157 (W463, 2013‑2018), common issues include oil leaks, turbocharger failure, and exhaust manifold leaks.

Is it worth replacing a G63 engine, or should I scrap the car?

Given the G63's exceptional retained value (typically £80,000–£150,000+), a £6,200–£9,000 reconditioned engine is a modest fraction of the vehicle's worth. Replacement is almost always financially viable. However, if the engine has suffered catastrophic failure (cylinder scoring, snapped timing chain), the total repair cost may be substantial. Get a full diagnostic assessment before committing.

How do I find my G63's engine code?

The W463 (2013‑2018) G63 uses the M157.984 – a 5.5‑litre V8 biturbo. The W464 (2019‑present) G63 uses the M177.980 – a 4.0‑litre V8 biturbo. The engine code is stamped on the engine block and listed on your V5C. The 2024‑onward models feature a 48V mild‑hybrid system.

Can I repair a G63 engine issue, or does it need replacement?

Most issues – rear main seal/oil separator failure (if caught early), turbocharger issues, oil leaks – are repairable. However, if cylinder scoring has occurred or the engine has suffered major internal failure, a full engine replacement is usually more cost‑effective than a rebuild. A rear main seal replacement on an M177 can cost 'well into the thousands'.

Mercedes‑AMG G632013–present2 Engine Generations

Mercedes‑AMG G63 Engine Replacement — Compare Prices & Get Quotes

Name: Mercedes‑AMG G63 UK Engine Enquiry Data 2025
Creator: MercedesEngine.uk

Get quotes today from trusted UK Mercedes specialists. Compare reconditioned, rebuilt and used M157 and M177 V8 biturbo engines for the G‑Class G63 AMG — the iconic, handcrafted V8 that defines the ultimate luxury off‑roader. Supply & fit available nationwide.

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Mercedes‑AMG G63 Engines — from £3,000 to £9,000Common codes: M157.984, M177.980

Mercedes‑AMG G63 Engines — from £3,000 to £9,000· Common codes: M157.984, M177.980

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Mercedes‑AMG G63 — Which Engine Does Your Car Actually Have?

Four generations. Four eras. One guide to reliability, costs and what really matters.

Era Note

544‑571 PS, 760 Nm — hot‑vee V8, runs extremely hot, oil leaks and turbo issues are common

GenerationYearsEngine CodeReliabilityRecon CostEra Note

W463 (Pre‑facelift) BMW 320d W463 (Pre‑facelift)

2013–2018M157.984 (5.5L V8 Bi‑Turbo)★★★½☆ [NEWLY ASSIGNED — see Data Note]£6,200–£7,900 [PLACEHOLDER — confirm vs cost sheet]544‑571 PS, 760 Nm — hot‑vee V8, runs extremely hot, oil leaks and turbo issues are common

W464 (2019–present) BMW 320d W464 (2019–present)

2019–presentM177.980 (4.0L V8 Bi‑Turbo)★★★☆☆ [NEWLY ASSIGNED — see Data Note]£7,000–£9,000 [PLACEHOLDER — confirm vs cost sheet]585 PS, 850 Nm — handcrafted M177, 48V mild‑hybrid from 2024, rear main seal and oil separator failures are defining weaknesses

Why use this era map?

This table is the single source every other section on this page must match. Sections 2, 4, and 6 reference it rather than restating conflicting figures.

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

Mercedes‑AMG G63 Engine Replacement Costs

Supply Only£6,200–£7,900

Fitted (Indie)£8,000–£10,000

Warranty12–24 months

Best ForMost owners — best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£3,000–£5,000£4,500–£7,0001–6 monthsBudget priority; short‑term ownership

Reconditioned Engine£6,200–£7,900£8,000–£10,00012–24 monthsMost owners — best cost/warranty balance

Rebuilt Engine£7,000–£9,000£9,000–£11,50012–24 monthsLong‑term ownership; maximum reliability

Main Dealer New£10,000–£14,000£12,000–£17,00024–36 monthsInsurance jobs; warranty claims; full provenance

Figures above reflect the G63 AMG pricing across generations. A replacement M157.984 engine costs on average £7,908 in good condition, with new or reconditioned units costing up to £7,930. Reconditioned M157 engines start from around £6,200. Reconditioned M177 engines are at the upper end of the range. Labour costs are higher than for conventional engines due to the hot‑vee design and the G‑Class's weight and packaging.

Labour estimate: Fitting a G63 AMG engine typically takes 16‑22 hours at £75‑£110/hr (independent Mercedes specialist). The hot‑vee design and the G‑Class's heavy, complex chassis add significant labour complexity. A rear main seal replacement on an M177 can cost "well into the thousands".

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Common Problems

1. M177 Rear Main Seal & Oil Separator Failure (W464, 2019–present)

Symptoms: Oil spots under the vehicle, burning oil smell, low oil level warning, visible oil leak from between the engine and transmission bell housing, increased oil consumption. As these vehicles accumulate mileage, one of the most frequent and expensive problems encountered is oil separator failure, which will often lead to rear main seal leaks.

Typical mileage: 30,000–60,000 miles — can occur on low to mid‑mileage cars.

Repair cost: £1,500–£4,000+ [PLACEHOLDER] (rear main seal and/or oil separator replacement — gearbox removal required).

Replacement cost: N/A — repair only (if caught early; ignored oil loss can lead to engine damage).

🟠 Check - book inspection urgently if oil leak is detected or oil consumption increases.

Our recommendation:

The M177 engine is prone to oil separator failure, which leads to rear main seal leaks. Both excessive positive pressure and excessive vacuum can damage seals, gaskets, and other engine components. Proper crankcase pressure balance is critical to the long‑term health of the M177 engine. If you notice oil spots under your G63 or a burning oil smell, have the oil separator and rear main seal inspected immediately. This is a labour‑intensive repair that requires gearbox removal — costs can run "well into the thousands".

1. M177 Rear Main Seal & Oil Separator Failure (W464, 2019–present)

Typical mileage: 30,000–60,000 miles — can occur on low to mid‑mileage cars.

Repair cost: £1,500–£4,000+ [PLACEHOLDER] (rear main seal and/or oil separator replacement — gearbox removal required).

Replacement cost: N/A — repair only (if caught early; ignored oil loss can lead to engine damage).

🟠 Check - book inspection urgently if oil leak is detected or oil consumption increases.

Our recommendation:

2. M177 Turbocharger Issues (W464, 2019–present)

Symptoms: Turbo lag, reduced boost pressure, loss of power, whistling or grinding noise from the engine bay, engine warning light, excessive exhaust smoke. Issues such as turbo lag, reduced boost pressure, or even premature wear of turbine components are not uncommon.

Typical mileage: 40,000–80,000 miles.

Repair cost: £1,500–£3,500 [PLACEHOLDER] (turbocharger replacement).

Replacement cost: N/A — repair only (if caught early; ignored turbo failure can send debris into the engine).

🟠 Check - book inspection urgently if you notice power loss or unusual noises.

Our recommendation:

The M177's twin turbochargers are critical in delivering the engine's substantial boost pressure. However, they are sensitive components that operate under intense thermal and mechanical stress. The M177 tends to have high oil and water temperatures even in series production. Regular inspections and timely servicing of the turbo system can help mitigate problems. If you notice turbo lag, reduced boost, or unusual noises, have the turbos inspected immediately.

3. Oil Leaks — Turbo Inlet Seal & Oil Cooler Seals (M157 & M177)

Symptoms: Oil spots under the vehicle, burning oil smell, low oil level warning, visible oil leak from the engine bay, rising oil temperature, limp mode.

Typical mileage: 40,000–80,000 miles.

Repair cost: £500–£2,000 [PLACEHOLDER] (turbo inlet seal or oil cooler seal replacement).

Replacement cost: N/A — repair only.

🟠 Check - book inspection urgently if oil leak is detected.

Our recommendation:

Oil leaks are one of the more frequent complaints with the M177 engine, often stemming from poorly sealed gaskets or oil pan issues. Turbo inlet seal leaks and oil cooler seal leaks are also common. The high operating temperatures and pressures cause increased oil consumption over time. Ignoring oil leaks can lead to accelerated engine wear, turbo failure, sludge buildup, and in worst cases, bearing damage or engine seizure. If you notice oil spots or a burning smell, investigate immediately.

4. M157 Exhaust Manifold / Header Leaks (W463, 2013–2018)

Symptoms: Ticking or tapping noise from the engine, especially when cold, exhaust smell in the cabin, reduced performance, engine warning light.

Typical mileage: 50,000–80,000 miles.

Repair cost: £1,000–£2,500 [PLACEHOLDER] (exhaust manifold gasket replacement).

Replacement cost: N/A — repair only.

🟠 Check - book inspection soon if you hear ticking or notice exhaust smell.

Our recommendation:

The M157's exhaust manifolds can develop leaks due to the extreme heat cycles of the hot‑vee design. Look for oil leaks around the passenger side manifold. A leaking manifold can cause ticking noises, exhaust fumes in the cabin, and reduced performance. If you hear ticking or notice an exhaust smell, have the manifold gaskets inspected.

5. M177 Cylinder Scoring (W464, 2019–present)

Symptoms: Misfire, loss of compression, rough running, engine warning light, increased oil consumption.

Typical mileage: 30,000–60,000 miles (can occur on hard‑driven examples).

Repair cost: £3,000–£8,000+ [PLACEHOLDER] (cylinder head replacement or engine rebuild).

Replacement cost: N/A — repair only.

🔴 Immediate - if you notice misfire or rough running, book an inspection immediately.

Our recommendation:

Mercedes has a tradition of cylinder scoring issues on engines. The surface coating can fail, causing scuffing and eventual loss of compression and misfire. Hard‑driven engines can have cylinder scoring. Proactively changing oil no greater than every 10,000 miles is essential. If you experience misfire or rough running, have the engine inspected immediately — cylinder scoring can be catastrophic.

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Mercedes‑AMG G63 — Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

Mercedes‑AMG G63 — Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

Can It Be Repaired?

ProblemRepairable?Typical CostWhen It Makes SenseM177 rear main seal / oil separator failure✅ Yes£1,500–£4,000+ [PLACEHOLDER]Essential maintenance — always worth doing on a high‑value vehicleM177 turbocharger issues✅ Yes£1,500–£3,500 [PLACEHOLDER]Worth fixing — common on high‑stress turbo enginesOil leaks (turbo inlet / oil cooler)✅ Yes£500–£2,000 [PLACEHOLDER]Essential maintenance — always worth doingM157 exhaust manifold leaks✅ Yes£1,000–£2,500 [PLACEHOLDER]Worth fixing — common on the M157M177 cylinder scoring⚠️ Sometimes£3,000–£8,000+Depends on damage extent — may require new head or engine replacementMajor internal failure (any engine)❌ Usually No£6,200–£9,000+Full engine replacement often more cost‑effective

Buying This Mercedes‑AMG G63? Check These First

Buy If

Full Mercedes service history with regular oil changes (every 8,000‑10,000 miles)
W464 (M177): Oil separator and rear main seal inspected — this is critical
W464 (M177): No oil leaks from the engine — turbo inlet and oil cooler seals should be dry
W463 (M157): Exhaust manifolds inspected and no ticking noises
A well‑maintained example — the G63 is a high‑value, high‑performance vehicle that demands attention

Avoid If

W464 (M177): Any sign of oil leaks — rear main seal or oil separator issues
W464 (M177): Any sign of turbo noise or reduced boost — turbocharger warning
W463 (M157): Any sign of ticking from the engine — exhaust manifold warning
Any sign of misfire or rough running — cylinder scoring warning
Poor service history — the M157 and M177 are intolerant of neglect

Closing Verdict

The Mercedes‑AMG G63 is the ultimate luxury off‑roader — a handcrafted V8 biturbo monster wrapped in iconic, boxy styling. The M157 (2013‑2018) and M177 (2019‑present) are engineering masterpieces, but they are high‑stress, high‑temperature engines with well‑documented weaknesses — rear main seal and oil separator failure (M177), turbocharger issues, oil leaks, and cylinder scoring. As one specialist noted, "Issues are possible but not probable. It's likely that the resulting repairs be more expensive than a less expensive engine in a less expensive car". Buy on service history above all else — a well‑maintained G63 is an extraordinary and rewarding vehicle; a neglected example can be ruinously expensive to repair.

Don't guess.Get the right engine at the right price.

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Buying Checklist

Before you buy a used Mercedes‑AMG G63 (or before you commit to an engine replacement), check these:

1. Oil Leaks — Check under the vehicle and around the engine for any signs of leakage (rear main seal, turbo inlet, oil cooler)

2. Cold Start — Any ticking or rattling? (exhaust manifold or timing chain warning)

3. Service History — Regular oil changes (every 8,000‑10,000 miles) — this is non‑negotiable

4. Turbo Health — Any whistling, lag, or smoke? (turbocharger warning)

5. Engine Serial Number — M177: Check for any known issues with specific production batches

6. Running Quality — Any misfire or rough running? (cylinder scoring warning)

7. Oil Consumption — Does it use more than 1L per 1,000 miles? (oil separator or seal warning)

8. MOT History — Check for emissions‑related failures or any advisory notes

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

Engine Codes

This table's rows match Section 1B's Era Map exactly.

M157.984 (5.5L V8 Bi‑Turbo)

Years2013–2018

Power544‑571 PS / 760 Nm

2025 Enquiries— (pattern data)

Avg. Recon Cost£6,200–£7,900 [PLACEHOLDER]

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

M157.984 (5.5L V8 Bi‑Turbo)2013–2018544‑571 PS / 760 Nm— (pattern data)£6,200–£7,900 [PLACEHOLDER]

M177.980 (4.0L V8 Bi‑Turbo)2019–present585 PS (430 kW) / 850 Nm— (pattern data)£7,000–£9,000 [PLACEHOLDER]

Technical Specs

M177.980 — 4.0L V8 Bi‑Turbo

Displacement5,461 cc

Cylinders8‑cylinder V8

Compression Ratio[VERIFY]

Fuel SystemDirect injection

AspirationBi‑Turbo

ValvetrainDOHC, 4 valves per cylinder

Drive4MATIC permanent all‑wheel drive

Displacement3,982 cc

Cylinders8‑cylinder V8

Bore x Stroke[VERIFY]

Compression Ratio8.6:1 / 10.5:1

Fuel SystemDirect injection

AspirationBi‑Turbo (twin‑scroll)

ValvetrainDOHC with VVT

Max Power585 PS (430 kW) at 6,000 rpm

Max Torque850 Nm at 2,500‑3,500 rpm

Mild‑Hybrid48V ISG from 2024, +20 bhp

0‑60 mph4.3 seconds

Kerb Weight2,560 kg / 2,640 kg

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Market Intelligence

Most Common Failure

M177: Rear main seal / oil separator failure — M157: Oil leaks and turbo issues

Average Enquiry Mileage

30,000

–60,000 miles

[PATTERN DATA]

Average Replacement Cost

£7,500

reconditioned, supply only

[PLACEHOLDER]

Most Requested Engine Code

M177.980 — the W464 generation is most common

[PATTERN DATA]

Peak Enquiry Season

Spring/Summer — luxury SUV interest peaks

[PATTERN DATA]

Regional Demand

South East22%

London18%

South West (12%) — premium SUV strongholds

PATTERN DATA

Regional Demand Breakdown

22%South East

18%London

Frequently Asked Questions

All prices are indicative UK market ranges based on historical quote data from our network of engine specialists. Actual costs vary by variant, engine code, damage severity and workshop location. Use our free comparison tool to get tailored quotes. Every engine supplied through EnginesMarket carries a minimum 12‑month unlimited‑mileage warranty — always confirm terms with your chosen supplier.

Why UK Mercedes‑AMG G63 Owners Trust MercedesEngine.uk

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every garage and engine rebuilder in our network is vetted, rated and reviewed by real G‑Class owners, as part of the Engine Finders network, covering both the M157 and M177 V8 biturbo engines with specialist knowledge of AMG's most powerful off‑road powertrains.
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see prices, warranty terms and supply & fit options side‑by‑side before you commit, with specialists who understand the M157's exhaust manifold vulnerabilities, the M177's rear main seal and oil separator issues, and the importance of rigorous maintenance intervals.
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supply‑only or full supply & fit available nationwide, covering both the W463 and W464 generations of the G63 AMG, with specialist knowledge of Mercedes‑AMG's handcrafted V8 engines.

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