Is the Mercedes S600 or S65 V12 engine reliable?

The M275 and M279 V12s are magnificent engines, but they have known, expensive weak points. The most notorious issues are ignition system failures (coil packs, voltage transformers, misfires), ABC hydropneumatic suspension problems, oil leaks from valve cover gaskets, and timing chain tensioner wear. The W222 S65 AMG with the M279 is the most refined and reliable of the V12 S-Class range. With proper maintenance, these engines can be very durable, but they demand serious financial commitment.

What are the common problems with the Mercedes S600 and S65 V12?

The most frequently reported issues are ignition system failures (coil packs, voltage transformers, misfires, ECU shutting down banks of cylinders), ABC suspension failures (warning lights, sagging, dangerously bouncy ride), valve cover gasket oil leaks, timing chain tensioner wear, and hot start stalling issues.

Is it worth replacing a Mercedes S600 or S65 V12 engine, or should I scrap the car?

Depends on vehicle value and condition. Against a well-kept £40,000 S65 AMG, a £7,000 recon is 17.5% — worth it. Against a tired £12,000 S600 example, the same recon approaches our 70% Mercedes threshold — get a scrap valuation first. Well-maintained V12 S-Class models are appreciating rapidly — a proper restoration is often justified for a clean example.

How do I find my Mercedes S600 or S65 V12 engine code?

Listed on the VIN plate and vehicle documentation. W220/W221 S600 (2000–2013): M275E55AL. W221 S65 AMG (2006–2013): M275E60AL. W222 S65 AMG (2013–2019): M279. The badge on the tailgate is the easiest tell — 'S 600' or 'S 65 AMG'.

Can I repair the ignition coils on the V12, or does it need full engine replacement?

Yes — ignition system repairs are well-understood. Early M275 engines use voltage transformers and coil packs that can be replaced. Later M279 engines use individual ignition coils. If you experience misfires, the ECU may shut down entire banks of cylinders to protect the catalytic converters. Diagnosis with STAR diagnostic equipment is essential to identify the specific failed component. In many cases, only the faulty coil needs replacement rather than all 12. If you notice any running issues, have the ignition system diagnosed immediately.

Mercedes S600 / S65 V122000–present2 Engine Generations

Mercedes S600 & S65 V12 Engine Replacement — Compare Prices & Get Quotes

Name: Mercedes S600/S65 V12 UK Engine Enquiry Data 2025
Creator: MercedesEngine.uk

Get quotes today from trusted UK Mercedes S-Class specialists. Compare reconditioned, rebuilt and used M275 and M279 5.5–6.0-litre twin-turbo V12 engines — from the flagship S600 to the range-topping AMG S65 — supply & fit available nationwide.

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Mercedes S600/S65 V12 Engines — from £3,500 to £15,000Common codes: M275, M279

Mercedes S600/S65 V12 Engines — from £3,500 to £15,000· Common codes: M275, M279

Instant QuotesNo Obligation100% FreeReconditionedRebuiltUsedSupply & Fit AvailableUK-Wide Network

The S600 / S65 V12 THROUGH TIME — Era Map

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

Era Note

The original S600 V12 — 493 hp, 590 lb-ft. Early coil packs, ABC suspension, and oil leaks are the main concerns.

GenerationYearsEngine CodeReliabilityRecon CostEra Note

W220 S600

2000–2006M275E55AL (5.5L V12 Twin-Turbo)★★★☆☆ [NEWLY ASSIGNED — see Data Note]£4,500–£8,000 [PLACEHOLDER — confirm vs cost sheet]The original S600 V12 — 493 hp, 590 lb-ft. Early coil packs, ABC suspension, and oil leaks are the main concerns.

W221 S600

2006–2013M275E55AL (5.5L V12 Twin-Turbo)★★★☆☆ [NEWLY ASSIGNED — see Data Note]£4,500–£8,000 [PLACEHOLDER]Refined S600 with revised M275. Still suffers from ignition transformer and ABC issues.

W221 S65 AMG BMW 320d W221 S65 AMG

2006–2013M275E60AL (6.0L V12 Twin-Turbo)★★★☆☆ [NEWLY ASSIGNED — see Data Note]£5,500–£10,000 [PLACEHOLDER]The original AMG V12 — 604 hp, 738 lb-ft. More power, same ignition and suspension vulnerabilities.

W222 S65 AMG BMW 320d W222 S65 AMG

2013–2019M279 (6.0L V12 Twin-Turbo)★★★½☆ [NEWLY ASSIGNED — see Data Note]£6,000–£12,000 [PLACEHOLDER]The final V12 S65 — 630 hp, 738 lb-ft. Revised M279 with individual coils; ABC remains a concern.

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 S600 / S65 V12 Engine Replacement Costs

Supply Only£5,500–£10,000

Fitted (Indie)£7,000–£12,000

Warranty12–24 months

Best ForMost owners — best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£3,500–£6,500£5,000–£8,0001–6 monthsBudget priority; lower-mileage examples

Reconditioned Engine£5,500–£10,000£7,000–£12,00012–24 monthsMost owners — best cost/warranty balance

Rebuilt Engine£8,000–£15,000£9,500–£17,00012–24 monthsLong-term ownership; 3+ year horizon

Main Dealer New£18,000–£25,000+£20,000–£28,000+24–36 monthsInsurance jobs, warranty claims

Figures above reflect the M275 and M279 V12 engines. A full engine replacement can run anywhere between £1,500 and £5,000 on average for standard engines, but V12 replacements are significantly more expensive. Reconditioned S600 V12 engines are available from specialist suppliers. Main dealer new engines can exceed £25,000.

Labour estimate: Fitting an S-Class V12 engine typically takes 20–30 hours at £80–£120/hr (independent) or £140–£200/hr (London/SE dealer). The V12's complexity and tight engine bay make this a specialist job requiring significant experience.

→ Compare S-Class V12 engine prices from UK specialists

Common Problems

1. Ignition System Failures — Coil Packs & Voltage Transformers (M275 & M279)

Symptoms: Misfires, rough running, engine warning light, loss of power, ECU cutting entire cylinder banks to protect catalytic converters, accelerated shuddering under load.

Typical mileage: 60,000–120,000 miles

Repair cost: £500–£2,000 (coil pack replacement — one or more units)【PLACEHOLDER — confirm vs cost sheet】

Replacement cost: £5,500–£15,000 (if ignition failure leads to catalytic converter or engine damage)

🟠 Check - book inspection urgently

Our recommendation:

The V12's ignition system is one of its most notorious weak points. Early M275 engines use voltage transformers and coil packs that frequently fail, causing misfires that can shut down entire banks of cylinders. One owner describes driving in cold weather when the left side of the engine completely shut down — "the classic coil pack failure where the ECU cuts the entire bank to protect the cats". Later M279 engines use individual coils, but failures still occur. The V12 requires 24 spark plugs, making ignition service costs significant. If you experience misfires or loss of power, have the ignition system diagnosed immediately.

Read the full ignition system failure guide

1. Ignition System Failures — Coil Packs & Voltage Transformers (M275 & M279)

Symptoms: Misfires, rough running, engine warning light, loss of power, ECU cutting entire cylinder banks to protect catalytic converters, accelerated shuddering under load.

Typical mileage: 60,000–120,000 miles

Repair cost: £500–£2,000 (coil pack replacement — one or more units)【PLACEHOLDER — confirm vs cost sheet】

Replacement cost: £5,500–£15,000 (if ignition failure leads to catalytic converter or engine damage)

🟠 Check - book inspection urgently

Our recommendation:

Read the full ignition system failure guide

2. ABC (Active Body Control) Suspension System Failures

Symptoms: "ABC Visit Workshop" warning on the dash, vehicle sagging after sitting overnight, uneven ride height, dangerously bouncy ride, suspension failure messages.

Typical mileage: 60,000–120,000 miles

Repair cost: £1,000–£5,000 (ABC system repair — accumulators, valve blocks, hoses, or pump)【PLACEHOLDER — confirm vs cost sheet】

Replacement cost: £5,500–£15,000 (if ABC failure leads to accident or secondary damage)

🔴 Immediate - if you see ABC warnings or notice sagging, stop and book inspection

Our recommendation:

The ABC hydropneumatic suspension is one of the most expensive systems to maintain on the S600 and S65. If an accumulator, valve block, or hydraulic line fails, the system can enter a dangerously bouncy state. One owner reports: "the orange 'ABC Malfunction' message comes on, all 4 corners get pumped up to their maximum height and the ride becomes dangerously bouncy". Left unchecked, a leaking hydraulic system can destroy the pump, leading to repairs exceeding £2,000. If you notice any ABC warnings, have the system inspected immediately.

Read the full ABC suspension failure guide

3. Oil Leaks — Valve Cover Gaskets & Timing Covers (M275 & M279)

Symptoms: Oil spots under the car, burning oil smell from the engine bay, low oil level warning, visible oil residue around the valve covers, oil in spark plug wells.

Typical mileage: 60,000–120,000 miles

Repair cost: £500–£1,500 (valve cover gasket replacement)【PLACEHOLDER — confirm vs cost sheet】

Replacement cost: £5,500–£15,000 (if oil leaks lead to engine damage or fire risk)

🟠 Check - book inspection urgently

Our recommendation:

Valve cover gasket oil leaks are common on the V12. The rubber seals degrade with age and heat, allowing oil to seep onto the engine. In some cases, oil can leak into the spark plug wells, wicking up into the ignition coil and destroying the PCB. There are reports of immediate oil leaks upon starting, which stop after oil pressure builds up. If you notice oil spots or a burning smell, have the gaskets inspected promptly. Ignoring oil leaks can lead to more serious engine damage or fire risk.

Read the full oil leak guide

Weighing Your Options?

Compare Specialist Quotes When You're Ready

25+ vetted Mercedes specialists, every S-Class V12 era covered — from the S600 to the S65 AMG — with a 12-month warranty as standard.

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S600 / S65 V12 — 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.

S600 / S65 V12 — 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 SenseIgnition coil pack failure✅ Yes£500–£2,000Well-understood repair; individual coils can be replacedABC suspension failure✅ Yes£1,000–£5,000Specialist repair; catch it early before pump failureValve cover gasket oil leak✅ Yes£500–£1,500Well-understood repair; cheaper than engine replacementVoltage transformer failure (M275)✅ Yes£300–£800Upgraded individual coil conversion availableTiming chain tensioner wear✅ Yes£1,500–£4,000Preventative — catches the fault before catastrophic failureMajor internal engine failure❌ Usually No£5,500–£15,000Typically requires full engine replacement or complete rebuild

Buying This S-Class V12? Check These First

Buy If

Full Mercedes service history with evidence of regular maintenance — these cars demand meticulous care
Ignition system recently serviced (coil packs, voltage transformers, plugs)
ABC suspension inspected and any leaks addressed
No oil leaks or evidence of recent gasket replacement
W222 S65 AMG preferred over older W220/W221 (improved ignition system)

Avoid If

ABC warning lights or suspension sagging (expensive repairs ahead)
Misfires or rough running with no ignition system history
Oil leaks with no documented repair history
Poor service history — the V12 is a masterpiece of engineering but unforgiving of neglect
Pre-2003 M275 with original coil pack design (updated individual coils are preferable)

Closing Verdict

The S600 and S65 V12 represent the absolute pinnacle of Mercedes engineering — a twin-turbocharged 5.5 or 6.0-litre V12 that delivers effortless, continent-crushing performance. The M275 is a masterpiece of the 2000s, while the M279 is its comprehensively revised successor. Both engines are magnificent but demand serious financial commitment. The two most expensive faults are the ignition system (coil packs and voltage transformers) and the ABC hydropneumatic suspension. Valve cover oil leaks are also common. The W222 S65 AMG with the M279 is the most refined and reliable of the V12 S-Class range. Buy on documented history, not on faith. A well-maintained S600 or S65 is a £20,000–£80,000 future classic; a neglected one is a £10,000+ repair bill waiting to happen.

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

→ Compare S-Class V12 engine prices before you buy

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Buying Checklist

Before you buy a used Mercedes S600 or S65 V12 (or before you commit to an engine replacement), check these:

Cold Start — Listen for misfires, rough running, or rattling (ignition or timing chain warning)

Service History — including which engine generation (M275 or M279) and confirmed maintenance records

Ignition Check — Any history of coil pack, voltage transformer, or misfire issues? (V12's most common problem)

ABC Suspension Check — Any warning lights, sagging, or bounce? (ABC is expensive to repair)

Oil Leak Check — Check for oil spots under the car or visible residue around valve covers

Hot Start Check — Any hesitation or stalling on hot starts? (fuel system or ignition warning)

Engine Warning Light — Have codes been read? Any unresolved ignition, ABC, or fuel system 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.

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

Technical Specs

M275 / M279

Displacement5,513 cc (M275 5.5) / 5,980 cc (M275 6.0 / M279)

CylindersV12, 60° configuration, SOHC, 3 valves per cylinder

Bore x Stroke82.0 mm × 85.0 mm (M275 5.5) / 82.6 mm × 93.0 mm (M279)

Compression Ratio9.0:1

Fuel SystemPort injection (sequential multi-point)

TurbochargerTwin turbochargers (biturbo)

IgnitionTwin spark plugs (24 spark plugs total)

BlockAluminium alloy

→ Compare S-Class V12 engine prices for your Mercedes

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Market Intelligence

Most Common Failure

Ignition system failures — coil packs and voltage transformers are the V12's most notorious weak points

Second Most Common

ABC (Active Body Control) suspension — expensive to repair and prone to failure

Average Enquiry Mileage

50,000

–100,000 miles

[PATTERN DATA]

Average Replacement Cost

£5,500

–£10,000 reconditioned, supply only

[PLACEHOLDER — confirm vs cost sheet]

Most Requested Engine Code

M275 / M279

[PATTERN DATA]

Peak Enquiry Season

Winter — cold starts expose ignition and ABC issues【PATTERN DATA】

Regional Demand

London22%

South East20%

South West15%

PATTERN DATA

Regional Demand Breakdown

22%London

20%South East

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.

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12-Month Warranty

As standard

Nationwide Delivery

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