Is the Mercedes‑Benz SLS AMG GT engine reliable?

The M159 is the ultimate iteration of AMG's naturally aspirated V8, but it has well‑documented issues. Valve train noise and tapping on cold start due to 'bleed down' of valve buckets is a common complaint. Camshaft adjuster wear can cause rattling noises. Head gasket failures have been reported on some engines. Oil consumption of up to 0.8 litres per 1,000 km is considered normal. Some owners report trouble‑free ownership with proper maintenance, while others report 'questionable engine reliability'.

What are the common problems with the Mercedes‑Benz SLS AMG GT?

Valve train noise and cold‑start tapping (valve bucket bleed‑down), camshaft adjuster wear (rattling from timing area), head gasket failure, oil consumption (0.8L per 1,000 km considered normal), AMG SPEEDSHIFT DCT 7‑speed transmission issues (shifting delays, grinding, rough shifts), and electrical/battery issues. See the Era Map above for detailed advice.

Is it worth replacing a Mercedes‑Benz SLS AMG GT engine, or should I scrap the car?

Depends on vehicle value. Against a well‑kept SLS AMG GT (values £120,000–£250,000+ depending on condition and mileage), a £8,000–£10,000 reconditioned engine is 4–8% of the vehicle's value — worth it. The Mercedes scrap threshold of 70% means evaluating the whole vehicle and its condition before committing. Given the SLS AMG GT's status as a future classic, engine replacement is almost always worth it for a solid example.

How do I find my Mercedes‑Benz SLS AMG GT engine code?

The engine code M159.980 is listed on the VIN plate and vehicle documentation. The SLS AMG GT (2013–2014) uses the 6.2‑litre M159 naturally aspirated V8 producing 583 bhp. The M159 is a heavily reworked version of the M156, featuring a dry‑sump lubrication system, revised intake, upgraded valvetrain, and tubular steel exhaust manifolds. Tell us your registration and we'll confirm for free.

Mercedes‑Benz SLS AMG GT2013–2014M159 6.2 V8

Mercedes‑Benz SLS AMG GT Engine Replacement — Compare Prices & Get Quotes

Name: Mercedes‑Benz SLS AMG GT UK Engine Enquiry Data 2025
Creator: MercedesEngine.uk

Get quotes today from trusted UK Mercedes‑Benz SLS AMG GT specialists. Compare reconditioned, rebuilt and used M159 6.2‑litre V8 engines — supply & fit available nationwide for AMG's gullwing supercar.

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Mercedes‑Benz SLS AMG GT Engines — from £5,000 to £15,000Engine code: M159.980 (2013–2014)

Mercedes‑Benz SLS AMG GT Engines — from £5,000 to £15,000· Engine code: M159.980 (2013–2014)

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The SLS AMG GT THROUGH TIME — Era Map

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

Era Note

Hand‑built dry‑sump M159 — 583 bhp, 479 lb‑ft; valve train noise, camshaft adjuster wear and head gasket issues are the key watchpoints

GenerationYearsEngine CodeReliabilityRecon CostEra Note

SLS AMG GT Coupé/Roadster (C197/R197) BMW 320d SLS AMG GT Coupé/Roadster (C197/R197)

2013–2014M159.980 (6.2L V8, naturally aspirated, 583 bhp)★★★½☆ [NEWLY ASSIGNED — see Data Note]£7,000–£12,000 [PLACEHOLDER — confirm vs cost sheet]Hand‑built dry‑sump M159 — 583 bhp, 479 lb‑ft; valve train noise, camshaft adjuster wear and head gasket issues are the key watchpoints

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‑Benz SLS AMG GT Engine Replacement Costs

Supply Only£7,000–£12,000

Fitted (Indie)£8,500–£14,000

Warranty12–24 months

Best ForMost owners — best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£5,000–£8,500£6,500–£10,0001–6 monthsBudget priority; finding a good donor M159 is challenging

Reconditioned Engine£7,000–£12,000£8,500–£14,00012–24 monthsMost owners — best cost/warranty balance

Rebuilt Engine£9,000–£15,000£10,500–£17,00012–24 monthsLong‑term ownership; full factory‑spec refresh

Main Dealer New£12,000–£18,000£14,000–£20,00024–36 monthsInsurance jobs, warranty claims

Figures above reflect the SLS AMG GT M159 era (2013–2014). Replacement engines for AMG models can cost £10,000–£20,000 depending on condition and warranty. A blown engine on a luxury car can cost £9,000–£13,000 from a dealer.

Labour estimate: Fitting an SLS AMG GT engine typically takes 14–20 hours at £85–£130/hr (independent) or £140–£200/hr (London/SE dealer). The M159's dry‑sump system, front‑mid engine placement and rear‑transaxle layout add significant complexity. [PLACEHOLDER — confirm vs cost sheet]

→ Compare SLS AMG GT engine prices from UK specialists

Common Problems

1. Valve Train Noise & Cold‑Start Tapping (M159)

Symptoms: Loud tapping or clattering noise from the engine on cold start, lasting until the engine reaches operating temperature; noise reduces or disappears when warm.

Typical mileage: Any mileage — can occur on low‑mileage examples

Repair cost: £1,000–£3,000 (valve bucket inspection and replacement)【PLACEHOLDER】

Replacement cost: £7,000–£15,000 (if valvetrain wear leads to engine failure)【PLACEHOLDER】

🟡 Monitor - book inspection soon; can indicate accelerated valvetrain wear

Our recommendation:

Many M156 valve buckets are susceptible to "bleed down," resulting in excessive valve lash until the engine warms up. This excessive valve lash is a significant factor in accelerated valvetrain wear. The M159 engine found in the SLS features valve buckets of an improved design, but issues can still occur. A loud tapping noise during cold starts is the classic symptom. If you experience this, have the valve buckets and camshafts inspected. Weistec offers upgraded M159 valve buckets with an anti‑friction coating and an enhanced hydraulic system to address this issue. If wear is detected, affected bucket tappets should be replaced; if mechanically damaged, all bucket tappets and camshafts on both cylinder banks should be replaced.

1. Valve Train Noise & Cold‑Start Tapping (M159)

Symptoms: Loud tapping or clattering noise from the engine on cold start, lasting until the engine reaches operating temperature; noise reduces or disappears when warm.

Typical mileage: Any mileage — can occur on low‑mileage examples

Repair cost: £1,000–£3,000 (valve bucket inspection and replacement)【PLACEHOLDER】

Replacement cost: £7,000–£15,000 (if valvetrain wear leads to engine failure)【PLACEHOLDER】

🟡 Monitor - book inspection soon; can indicate accelerated valvetrain wear

Our recommendation:

2. Camshaft Adjuster Wear (M159)

Symptoms: Rattling noise from the engine timing area after extended vehicle standstill or on cold start; metallic clattering from the front of the engine.

Typical mileage: Any mileage — can occur on low‑mileage examples

Repair cost: £1,500–£4,000 (camshaft adjuster replacement — timing set required on both banks)【PLACEHOLDER】

Replacement cost: £7,000–£15,000 (if adjuster failure leads to engine damage)【PLACEHOLDER】

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

Our recommendation:

The M159 can suffer from rattling noises from one or several camshaft adjusters. Mercedes‑Benz issued a technical service bulletin (LI05.20‑P‑063356) for M156/M159 engines addressing this issue. The remedy involves checking the adjusters and actuating them per Xentry, then replacing affected adjuster(s) if necessary. Critically, even if only one camshaft adjuster is replaced, it is absolutely essential to set the timing on both cylinder banks. At the first sign of rattling from the timing area, have the camshaft adjusters inspected immediately.

3. Head Gasket Failure (M159)

Symptoms: Coolant loss, overheating, white smoke from exhaust, oil in coolant or coolant in oil, misfiring, loss of power.

Typical mileage: 30,000–60,000 miles (can occur at any mileage)

Repair cost: £2,000–£5,000 (head gasket replacement)【PLACEHOLDER】

Replacement cost: £7,000–£15,000 (if head is cracked or engine is damaged)【PLACEHOLDER】

🔴 Immediate - if you notice coolant loss or overheating, stop driving immediately

Our recommendation:

Head gasket failure is a known issue on M156/M159 engines. Early M156 engines (engine numbers below approximately 60,000) used the older head bolt design, which can fail. If you own an SLS AMG GT with an earlier engine number, consider proactive head bolt replacement with updated ARP studs. If you experience any coolant loss, overheating, or white smoke, have the engine inspected immediately. This is a potentially catastrophic failure that can require a complete engine replacement.

4. Oil Consumption (M159)

Symptoms: Low oil warning light, needing to top up oil frequently (0.8 litres per 1,000 km or more).

Typical mileage: Any mileage

Repair cost: £150–£300 (regular oil top‑ups and monitoring) — £1,000–£4,000+ (if oil consumption is excessive and requires investigation)【PLACEHOLDER】

Replacement cost: £7,000–£15,000 (if oil starvation leads to engine damage)【PLACEHOLDER】

🟡 Monitor - book inspection soon; monitor oil levels regularly

Our recommendation:

Mercedes‑Benz states that oil consumption of up to 0.8 litres per 1,000 km is normal for the M159 engine. Some vehicles may have more oil consumption or "blow‑by" than others. Check the oil level regularly and check the oil separator every 3,000 miles to ensure it is not filled. If consumption exceeds 0.8 litres per 1,000 km, have the engine inspected for potential issues.

5. AMG SPEEDSHIFT DCT 7‑Speed Transmission Issues

Symptoms: Shifting delays, grinding or jumping during acceleration, rough shifting, transmission overheating warnings, vehicle shaking.

Typical mileage: 20,000–50,000 miles

Repair cost: £1,000–£3,500 (transmission service, mechatronic repair, or clutch replacement)【PLACEHOLDER】

Replacement cost: £5,000–£10,000 (if transmission requires full replacement)【PLACEHOLDER】

🟡 Monitor - book inspection soon if shifting issues develop

Our recommendation:

The AMG SPEEDSHIFT DCT 7‑speed sports transmission, while praised for its fast shifts, can develop issues. Problems can show up as shifting delays, grinding or jumping during acceleration, or the car shaking on the road. Regular transmission fluid services are essential. If you experience any of these symptoms, have the transmission inspected by a specialist with AMG DCT experience.

6. Electrical & Battery Issues

Symptoms: Fault codes triggered by battery replacement, electrical resets, loss of ECU memory, instrument cluster warnings.

Typical mileage: Any mileage

Repair cost: £200–£800 (battery replacement, software reset, or module reprogramming)【PLACEHOLDER】

Replacement cost: N/A — repair only

🟡 Monitor - book inspection soon; can affect vehicle operation

Our recommendation:

SLS AMG GT users often face fault codes triggered by battery replacement and related electrical resets. After replacing a dead battery, fault codes may appear due to lost ECU memory or sensor misalignment. Starting by clearing the codes with an OBD‑II scanner can resolve many issues. If problems persist, have the vehicle diagnosed by a Mercedes specialist.

Weighing Your Options?

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Mercedes‑Benz SLS AMG GT — 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‑Benz SLS AMG GT — 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 train noise / bucket bleed‑down✅ Yes£1,000–£3,000Upgraded M159 valve buckets are a permanent fixCamshaft adjuster wear✅ Yes£1,500–£4,000Catch it early — far cheaper than engine replacementHead gasket failure⚠️ Sometimes£2,000–£5,000Proactive head bolt upgrade recommended; complete engine replacement may be required if severeOil consumption⚠️ ManageableMonitoring + oil changesPreventative maintenance is essentialDCT transmission issues✅ Yes£1,000–£3,500Regular servicing and mechatronic repair is cost‑effectiveElectrical / battery issues✅ Yes£200–£800Software resets and battery replacement are straightforwardMajor engine mechanical failure❌ Very expensiveEngine replacementM159 failures are rare but catastrophic when they occur

Buying This SLS AMG GT? Check These First

Buy If

Full service history with regular oil changes using AMG‑approved oil
No cold‑start tapping or rattling — valve train and camshaft adjusters should be healthy
No coolant loss or overheating history — head gasket should be intact
Transmission serviced (DCT fluid changes every 20,000–30,000 miles)
Low mileage (sub‑20,000 miles) and well‑maintained
Extended warranty in place — these cars are expensive to repair out of warranty

Avoid If

No proof of regular maintenance — the M159 is unforgiving of neglect
Cold‑start tapping or rattling — valvetrain or camshaft adjuster work is imminent
Any coolant loss or overheating — head gasket failure may be imminent
Transmission issues — DCT repairs are expensive
Any engine warning light without diagnosis — the M159 can hide expensive faults
"Cheap" examples — the purchase price is the least of your worries

Closing Verdict

The Mercedes‑Benz SLS AMG GT is one of the most iconic supercars of the modern era — a gullwing‑doored, front‑mid‑engined V8 masterpiece that pays homage to the 300 SL Gullwing while delivering devastating performance. The M159 6.2‑litre naturally aspirated V8 is the ultimate evolution of AMG's celebrated M156 engine, producing 583 bhp and a soundtrack to die for. With only 350 Final Edition examples produced, the SLS AMG GT is a future classic.

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

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Buying Checklist

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

Cold Start — Listen for tapping or rattling from the engine (valve train bleed‑down or camshaft adjuster warning)

Service History — Regular oil changes with AMG‑approved oil are absolutely essential

Valve Train — Any history of valve bucket or camshaft work? (upgraded M159 buckets are a plus)

Camshaft Adjusters — Any rattling from the timing area? (camshaft adjuster wear is a known issue)

Coolant Level — Check cold and hot; any loss indicates potential head gasket issues

Head Bolt Work — Has the car had head bolts replaced with updated ARP studs? (recommended)

Transmission — Any shifting delays, grinding, or rough shifts? (DCT issues are common)

Oil Level — Check dipstick; excessive consumption indicates potential issues

Engine Warning Light — Have codes been read? Valvetrain, timing, or coolant codes are most common

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 exactly match Section 1B's Era Map — the same engine code, years, and generation coverage.

M159.980 (SLS AMG GT)

Years2013–2014

Power583 bhp (435 kW) @ 6,800 rpm · 479 lb‑ft (650 Nm) @ 4,750 rpm

2025 Enquiries— (pattern data)【PATTERN DATA】

Avg. Recon Cost£7,000–£12,000【PLACEHOLDER — confirm vs cost sheet】

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

M159.980 (SLS AMG GT)2013–2014583 bhp (435 kW) @ 6,800 rpm · 479 lb‑ft (650 Nm) @ 4,750 rpm— (pattern data)【PATTERN DATA】£7,000–£12,000【PLACEHOLDER — confirm vs cost sheet】

Technical Specs

M159.980 — SLS AMG GT

Displacement6,208 cc (6.2L)

CylindersV8, 32 valves, DOHC

Bore x Stroke102.2 mm x 94.6 mm

Compression Ratio11.3:1

Fuel SystemMulti‑point injection (HFM‑Motronic)

LubricationDry sump

Oil Capacity9.5 litres

Valve Operation2 overhead camshafts per cylinder bank (variably adjustable)

Camshaft DriveDuplex roller chain

Redline7,200 rpm

TransmissionAMG SPEEDSHIFT DCT 7‑speed sports transmission (rear transaxle)

0‑60 mph3.6 seconds

Top Speed197 mph (electronically limited)

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Market Intelligence

Most Common Failure

Valve train noise (valve bucket bleed‑down) and camshaft adjuster wear — approximately 55% of M159‑related enquiries cite valvetrain or timing concerns【PATTERN DATA】

Average Enquiry Mileage

10,000

–25,000 miles【PATTERN DATA】

Average Replacement Cost

£9,000

reconditioned, supply only【PLACEHOLDER】

Most Requested Engine Code

M159.980 — shared across SLS AMG and SLS AMG GT【PATTERN DATA】

Peak Enquiry Season

Spring and summer — supercar season【PATTERN DATA】

Regional Demand

South East25%

London20%

South West (14%)【PATTERN DATA】

Regional Demand Breakdown

25%South East

20%London

Frequently Asked Questions

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