Mercedes-Benz C-Class C63 AMG Engine Replacement Compare Prices & Get Quotes

A replacement engine for a C63 AMG typically costs between £3,500 and £16,000 depending on the generation and condition. Used M156 units start from £3,500-£6,500, reconditioned from £6,500-£10,000, and fully rebuilt M177 engines from £9,000-£16,000. Labour for supply & fit adds £800-£1,500 for AMG-specialist work. High-performance AMG engines have replacement costs exceeding £10,000.

• Used M156.985 (W204 C63): £3,500-£6,500
• Rebuilt M156.985: £8,000-£15,000
• Rebuilt M177.980 (W205 C63): £9,000-£16,000

Early M156 engines (pre-2011, engine numbers below 60-060658) suffer from defective head bolts that can snap, allowing coolant to enter the combustion chamber. Early warning signs include a low coolant light, misfires, coolant in the oil, and a check engine light. Failures typically occur between 40,000 and 50,000 miles. Repair costs at a specialist are approximately £1,600-£2,400 for preventative replacement.

• Affects pre-2011 W204 C63 AMG
• Low coolant light and misfires are warning signs
• Preventative replacement at specialist: £1,600-£2,400

Both the M156 (W204) and M177 (W205) engines use timing chains, not belts. The M156 uses a timing chain with camshaft adjusters that can wear, causing a rattling noise on cold start. The M177 uses a timing chain with "hot-vee" twin-turbo layout. A rattling noise on cold start is the classic warning sign for timing chain or camshaft adjuster issues.

• M156: timing chain - camshaft adjuster wear is common
• M177: timing chain - generally robust with proper maintenance
• Cold-start rattle indicates camshaft adjuster or tensioner wear

On M156-equipped models (W204 C63, 2007-2014), common symptoms include: a rattling or ticking noise on cold start (camshaft adjuster/lifter wear), low coolant light or misfires (head bolt failure), and rough idle (intake valve carbon buildup). On M177-equipped models (W205 C63, 2015-2021), symptoms include: rough running (fuel injector leaks), overheating (cooling system strain), and whistling noises or oil leaks (PCV/rear main seal issues).

• M156: cold start rattle - camshaft adjuster issue
• M156: low coolant - head bolt failure
• M177: rough running - injector leaks

It depends on the generation and condition. A W204 C63 AMG is typically worth £10,000-£25,000 - a rebuilt M156 engine (£8,000-£15,000) can be a worthwhile investment if the car is in good condition. A W205 C63 AMG is worth £15,000-£40,000 - a rebuilt M177 engine (£9,000-£16,000) is usually well within the car's value. For the M156, preventative head bolt replacement is the most cost-effective approach if caught early.

• W204 (2007-2014): preventative head bolt replacement or rebuilt M156 viable
• W205 (2015-2021): rebuilt M177 usually justifies cost
• Vehicle worth over £15,000: replacement usually justifies the cost

The M156 is a 6.2-litre naturally aspirated 90° V8 used in the W204 C63 AMG (2007-2014), producing 451-487 hp. It is AMG's first independently developed engine. The M177 is a 4.0-litre twin-turbo V8 with a "hot-vee" layout used in the W205 C63 AMG (2015-2021), producing 476-510 hp. The M177 replaced the M156 with more power and better efficiency, though some enthusiasts prefer the naturally aspirated character of the M156.

• M156: 6.2L, naturally aspirated, 451-487 hp, W204 (2007-2014)
• M177: 4.0L, twin-turbo, 476-510 hp, W205 (2015-2021)
• M156 has head bolt weakness; M177 has injector and cooling issues