Is the Mercedes G500 (M113 V8) engine reliable?

Yes — the M113 is widely regarded as one of Mercedes' most robust and reliable engines. It's a simple, 3‑valve SOHC V8 that can exceed 200,000 miles with regular maintenance. The main watchpoints are valve stem seal wear, oil leaks and timing chain tensioners — all manageable with preventative maintenance.

What are the common problems with the G350 / G500 Petrol engine?

Valve stem seal wear (blue smoke on startup, increased oil consumption), oil leaks from camshaft position sensors and valve covers, timing chain tensioner wear (cold‑start rattle), and EGR valve clogging. The engines are fundamentally robust when properly maintained.

Is it worth replacing a G350 / G500 Petrol engine, or should I scrap the car?

Depends on vehicle value and engine condition. A W463 G500 is a £15,000–£45,000+ vehicle — a £5,000–£6,000 recon is 11–40% of the car's value, making replacement viable in most cases. A well‑maintained, lower‑mileage example justifies replacement; a tired, high‑mileage one may not.

How do I find my Mercedes G350 / G500 Petrol engine code?

Listed on the VIN plate and vehicle documentation. The G500 uses the M113 (5.0‑litre V8, engine code M113.962). The G350 (or G320 in some markets) uses the M112 (3.2‑litre V6). Tell us your registration date and we'll confirm which one you have for free.

Can I prevent the common failures on a G350 / G500 Petrol?

Yes — regular oil changes with Mercedes‑approved oil and shortened intervals (5,000–7,500 miles) are the most effective prevention. On the M113, listen for blue smoke on startup — this indicates valve stem seal wear. At the first sign of cold‑start rattle, blue smoke or oil leaks, book an inspection immediately.

Mercedes G‑Class G350 / G500 Petrol1998–2015M112 / M113

Mercedes G‑Class G350 / G500 Petrol Engine Replacement — Compare Prices & Get Quotes

The G350 and G500 represent the petrol‑powered heart of the classic W463 G‑Class — the M112 V6 and the legendary M113 V8. Get quotes from trusted UK specialists today.

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Mercedes G350 / G500 Petrol Engines — from £2,000 to £8,500M112 / M113

Mercedes G350 / G500 Petrol Engines — from £2,000 to £8,500· M112 / M113

Instant QuotesNo Obligation100% FreeReconditionedRebuiltUsedSupply & Fit AvailableUK-Wide Network

The G350 / G500 PETROL THROUGH TIME — Era Map

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

GenerationYearsEngine CodeReliabilityRecon CostEra Note

Why use this era map?

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

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

Mercedes G‑Class G350 / G500 Petrol Engine Replacement Costs

Supply Only£4,500–£7,500

Fitted (Indie)£5,800–£9,000

Warranty12–24 months

Best ForMost owners — best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£2,000–£4,500£3,000–£6,0001–6 monthsBudget priority; lower‑mileage donor

Reconditioned Engine£4,500–£7,500£5,800–£9,00012–24 monthsMost owners — best cost/warranty balance

Rebuilt Engine£6,000–£8,500£7,300–£10,20012–24 monthsLong‑term ownership; 3+ year horizon

Main Dealer NewN/A — no longer availableN/AN/ANot available — reconditioned only

Figures above reflect the range across both engine families; specific costs vary by engine — see the Era Map above. A reconditioned M113 V8 engine typically costs between £4,500 and £7,500 supply only. A replacement M113 engine costs on average £2,865 in good condition, with reconditioned units reaching higher figures.

Labour estimate: Fitting a G‑Class V8 engine typically takes 14–18 hours at £65–£95/hr (independent) or £110–£160/hr (London/SE dealer). The G‑Class engine bay is spacious but the weight of the V8 requires specialist equipment.

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Common Problems

1. Valve Stem Seal Wear (M113 & <a href='https://mercedesengines.uk/engine/m112'>M112</a> — All Years)

Symptoms: Blue smoke on startup (particularly after idling), excessive oil consumption (1L per 1,000 miles+), fouled spark plugs, occasional misfire.

Typical mileage: 80,000–150,000 miles

Repair cost: £1,500–£4,000 (valve stem seal replacement)

Replacement cost: N/A — repair only (if caught before catalytic converter damage)

🟡 Monitor - book inspection soon

Our recommendation:

Valve stem seal wear is the most common issue on the M113 V8. The seals harden over time, allowing oil to leak into the combustion chamber on startup. If you see blue smoke on startup or notice increasing oil consumption, have the valve stem seals inspected. Replacing them is labour‑intensive but far cheaper than a full engine replacement. Some owners report that using high‑mileage oil can temporarily reduce consumption, but the only permanent fix is seal replacement.

1. Valve Stem Seal Wear (M113 & <a href='https://mercedesengines.uk/engine/m112'>M112</a> — All Years)

Symptoms: Blue smoke on startup (particularly after idling), excessive oil consumption (1L per 1,000 miles+), fouled spark plugs, occasional misfire.

Typical mileage: 80,000–150,000 miles

Repair cost: £1,500–£4,000 (valve stem seal replacement)

Replacement cost: N/A — repair only (if caught before catalytic converter damage)

🟡 Monitor - book inspection soon

Our recommendation:

2. Oil Leaks — Camshaft Sensors & Valve Covers (M113 & M112)

Symptoms: Oil spots under the vehicle, burning oil smell, oil residue on the engine, oil leaking into the wiring harness.

Typical mileage: 60,000–120,000 miles

Repair cost: £400–£1,200 (camshaft sensor seals, valve cover gaskets)

Replacement cost: N/A — repair only

🟡 Monitor - book inspection soon

Our recommendation:

Oil leaks are a common issue on the M113 as it ages. Camshaft position sensors can leak oil into the wiring harness, potentially causing electrical gremlins. Valve cover gaskets also degrade over time. If you notice oil spots or a burning smell, have the engine inspected. Replacing gaskets and seals promptly prevents more serious damage and expensive wiring harness repairs.

3. Timing Chain Tensioner Wear (M113 & M112)

Symptoms: Rattling noise on cold start (lasting 1–3 seconds), metallic ticking, engine warning light with timing‑related fault codes (P0016, P0017, P0018).

Typical mileage: 100,000–200,000 miles

Repair cost: £1,200–£3,000 (tensioners, chain guides and chain replacement)

Replacement cost: £4,500–£8,500 (full engine replacement if chain jumps)

🔴 Immediate - if you hear rattle, book an inspection today

Our recommendation:

The M113's timing chain tensioners are a known wear point — they rely on oil pressure to maintain tension. If the tensioner fails, the chain can develop slack, resulting in a characteristic rattle on cold start. If left unaddressed, the chain can jump a tooth, risking bent valves and costly repairs. Regular oil changes with Mercedes‑approved oil are essential. At the first sign of cold‑start rattle, have the timing chain system inspected immediately.

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G350 / G500 Petrol — 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.

G350 / G500 Petrol — 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 SenseValve stem seal wear✅ Yes£1,500–£4,000Labour‑intensive but cheaper than replacementOil leaks — cam sensors & valve covers✅ Yes£400–£1,200Straightforward — do preventativelyTiming chain tensioner wear✅ Yes£1,200–£3,000Catch it early — before chain jumpsEGR valve clogging✅ Yes£200–£500Routine maintenance — clean or replaceSevere engine damage (chain jump / overheating)❌ Usually NoEngine replacementLittle left to salvage — replacement is the only option

Buying This G350 / G500 Petrol? Check These First

Buy If

M113 (G500): no blue smoke on startup — valve stem seals in good condition
No cold‑start rattle — timing chain tensioners in good condition
No oil leaks — camshaft sensors and valve covers dry
Full Mercedes service history with regular oil changes

Avoid If

Blue smoke on startup — valve stem seals may be failing — walk away
Cold‑start rattle with no tensioner history — timing chain issues likely
Oil leaks with no diagnosis — potentially expensive
Poor service history — M113 engines are robust but sensitive to neglect

Closing Verdict

The M113 V8 is one of Mercedes' most robust and reliable engines — a 5.0‑litre, 3‑valve SOHC V8 that delivers effortless torque and legendary durability. The M112 V6 is equally robust but less common. Both are chain‑driven, relatively simple and capable of high mileage. The main watchpoints — valve stem seals, oil leaks and timing chain tensioners — are well‑understood and manageable. Buy on full service history, check for blue smoke on startup, and never ignore a cold‑start rattle. A well‑maintained G500 is a future classic; a neglected one is a £5,000+ bill waiting to happen.

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

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Buying Checklist

Before you buy a used Mercedes G‑Class G350 / G500 Petrol (or before you commit to an engine replacement), check these:

Cold Start — Listen for rattling; timing chain tensioner indicator

Blue Smoke — Check on startup; valve stem seal wear indicator

Oil Leaks — Check under the car and around the engine; camshaft sensors and valve covers

Service History — including which engine (M112 or M113) and confirmed oil‑change intervals

Oil Consumption — Does it use more than 1L per 1,000 miles? Valve stem seal indicator

Engine Vibration — Check for rough idle or misfire; timing or ignition issues possible

Engine Warning Light — Have codes been read? Any unresolved timing or sensor issues?

MOT History — Check for emissions‑related failures

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.

M112 (3.2 V6)

Years1998–2015

Power215–240 hp

2025 Enquiries— (pattern data)

Avg. Recon Cost£3,500–£6,000【PLACEHOLDER】

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

M112 (3.2 V6)1998–2015215–240 hp— (pattern data)£3,500–£6,000【PLACEHOLDER】

M113 (5.0 V8)1998–2015296–302 hp (218 kW) @ 5,600 rpm; 336‑460 Nm @ 2,700–4,250 rpm— (pattern data)£4,500–£7,500【PLACEHOLDER】

Technical Specs

M113 5.0 V8

Displacement4,966 cc

Cylinders8‑cylinder V‑configuration

Compression Ratio10.0:1

Fuel SystemMulti‑port fuel injection

ValvetrainSOHC with 3 valves per cylinder

Engine Oil Capacity8.0 litres

Timing DriveChain

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Market Intelligence

Most Common Failure

Valve stem seal wear — the most frequently reported M113 issue【PATTERN DATA】

Average Enquiry Mileage

80,000

–120,000 miles【PATTERN DATA】

Average Replacement Cost

£5,500

reconditioned, supply only【PLACEHOLDER — confirm vs cost sheet】

Most Requested Engine Code

M113 (G500) — approximately 80% of G‑Class petrol enquiries【PATTERN DATA】

Peak Enquiry Season

Autumn/Winter — cold starts expose valve seal and timing chain issues【PATTERN DATA】

Regional Demand

South East18%

London16%

South West (14%)【PATTERN DATA】

Regional Demand Breakdown

18%South East

16%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.

Find the best Mercedes G‑Class G350 / G500 Petrol engine replacement UK drivers rely on. Compare prices from trusted specialists on EnginesMarket today and get back on the road with confidence — from £2,000 for a used unit to £8,500 for a fully rebuilt V8.

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12-Month Warranty

As standard

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