Mercedes AMG GT M178/M177 Performance Engine ReplacementRebuilt & Options

A rebuilt M178 V8 costs £8,000-£16,000 supply-only, rising to £14,000-£22,000 for a Black Series flat-plane crank unit. Prices vary by variant, engine code and whether you need supply & fit.

• Base M178 (GT/GT S): £8,000-£15,000 for a rebuilt unit
• Performance M178 LS2 (GT R): £11,000-£19,000 supply-only
• Black Series M178 LS3: £15,000-£22,000 - limited availability
• Supply & fit adds £800-£1,500 to any engine price

Timing chain stretch (50k-80k miles) is the #1 failure on M178 engines, followed by turbo actuator failure and hot-vee coolant crossover pipe leaks. Valve stem seal hardening also causes oil consumption.

• Timing chain stretch leads to valve contact - replace chains preventatively
• Turbo actuator electronics fail from heat exposure in the hot-vee
• Plastic coolant pipes crack between cylinder banks - upgrade to aluminium
• Viton valve stem seals solve oil consumption on early M178 LS1 units

On a GT worth £35k-£80k, preventative chain replacement is cost-effective. If the engine has already failed, a fully rebuilt unit with upgraded timing components and seals is usually better value than repairing the damaged original.

• Preventative chain replacement at a specialist: £2,400-£3,200
• Repairing a slipped chain with head work: £4,500-£6,500
• Fully rebuilt M178 with upgrades and warranty: £9,000-£16,000
• Matching numbers matter for collectable Black Series and GT R Pro

Well-maintained M178 engines regularly reach 100k-120k miles. The key is addressing timing chain stretch before it fails - typically around 50k-80k miles. Cars used on track wear chains faster.

• Timing chain service interval effectively 50k-80k miles on early cars
• Turbo actuator life: 40k-70k miles depending on heat exposure
• Valve stem seals typically last 45k-75k miles before hardening
• Late C190 units (2019+) have revised chain guides for longer life

Check your VIN - digits 4-8 contain the engine code. GT and GT S use M178/M178 LS1, GT R uses M178 LS2, Black Series uses M178 LS3. C192 models (2024+) use M177 (V8) or M139 (four-cylinder).

• M178: Base GT (462-476hp) and GT C (550-557hp)
• M178 LS1: GT S (510-522hp) and early GT variants
• M178 LS2: GT R, GT R Pro (577-585hp)
• M178 LS3: Black Series only (720-730hp flat-plane crank)

Yes, the M178 LS2 from a GT R is a direct physical swap into any C190 coupe. However, you'll need the LS2-specific ECU calibration, turbo oiling upgrades, and potentially the GT R's auxiliary oil cooler.

• Physical mounting points are identical across all M178 engines
• ECU must be reprogrammed with LS2 maps - not a plug-and-play swap
• GT R uses uprated turbo bearings and revised oiling passages
• Specialist fitting recommended - budget £11,000-£19,000 for the complete job

Every engine supplied through EngineMarket carries a minimum 12-month unlimited mileage warranty. Many reconditioned and remanufactured units from specialist AMG rebuilders include 24-month coverage.

• Standard warranty: 12 months unlimited mileage on all engine types
• Reconditioned/remanufactured units: Often 24 months from AMG specialists
• Supply & fit packages: Labour warranty included with fitting (12 months)
• Black Series LS3 engines: Limited supply, always confirm warranty terms

Supply-only delivery takes 2-5 working days. Full supply and fit by an AMG specialist typically takes 3-5 days, including removal, installation, fluids, and first-start diagnostics.

• Used engine delivery: 2-3 days from UK breaker network
• Rebuilt/reconditioned engine delivery: 5-10 days (built to order)
• Supply & fit turnaround: 3-5 days at a fixed workshop
• Mobile fitting: Available nationwide, add 1-2 days for travel scheduling

Yes, specialist rebuilders offer upgraded M178 units with double-row timing chains, aluminium coolant crossover pipes, Viton valve stem seals, and reinforced turbo actuators - all addressing the original failure points.

• Upgraded timing chain kit: Eliminates stretch risk completely
• Aluminium crossover pipe: Permanent fix for hot-vee coolant leaks
• Viton valve stem seals: Solve oil consumption on LS1 engines
• Upgraded turbo actuators: Heat-resistant electronics for longer life

Yes, many of our specialist suppliers offer core credit for your failed M178, M177 or M139 engine. The credit typically ranges from £1,000-£3,000 depending on the engine code and whether the block is salvageable.

• M178 core credit: £1,500-£3,000 for rebuildable units
• M139 (four-cylinder) credit: £800-£1,500 - lower demand
• Black Series LS3 cores: Valued higher - contact us for a quote
• Engine must be complete (no missing turbos or ancillaries)