Mercedes-Benz C-Class 250 Petrol Engine Replacement Compare Prices & Get Quotes

A replacement engine for a C250 petrol typically costs between £600 and £4,800 depending on the engine code and condition. Used M271 units start from £600-£1,500, reconditioned from £1,800-£3,000, and fully rebuilt M274 engines from £2,500-£4,800. Labour for supply & fit adds £500-£1,000.

• Used M271.860 (W204 C250 CGI): £600-£1,500
• Rebuilt M271.860: £2,200-£3,800
• Rebuilt M274.920 (W205 C250): £2,500-£4,800

The M271 is a 1.8-litre turbocharged four-cylinder engine used in the W204 C250 CGI (2011-2014), producing 204 hp with a single-row timing chain. The M274 is a 2.0-litre turbocharged four-cylinder engine used in the W205 C250 (2014-2018), producing 211 hp. The M274 replaced the M271 and offers more power and torque, but suffers from a wrist pin/piston seizure defect. The M271 is more prone to timing chain stretch and camshaft adjuster failure.

• M271: 1.8L, 204 hp, timing chain stretch risk, W204 (2011-2014)
• M274: 2.0L, 211 hp, wrist pin/piston risk, W205 (2014-2018)

Both the M271 and M274 engines use timing chains, not belts. The M271 uses a single-row timing chain that is considered a wear item - failure typically occurs between 60,000-100,000 miles. The M274 also uses a timing chain, but it is generally more robust than the M271's chain. A rattling noise from the front of the engine on cold start is the classic warning sign for timing chain issues.

• M271: timing chain - prone to stretch at 60k-100k miles
• M274: timing chain - more robust but requires regular oil changes

On M271-equipped models (W204 C250 CGI, 2011-2014), the most common symptom is a rattling noise from the front of the engine on cold start, rough idle, hesitation, poor fuel economy, and power loss. On M274-equipped models (W205 C250, 2014-2018), symptoms include unusual engine noise, particularly on start-up, and potential sudden engine failure.

• Rattling on cold start - timing chain issue (M271)
• Unusual engine noise - wrist pin issue (M274)
• Loss of power - timing or piston issues

It depends on the generation and condition. A W204 C250 CGI is typically worth £4,000-£9,000 - a rebuilt M271 engine (£2,200-£3,800) can be a worthwhile investment if the car is in good condition. A W205 C250 is worth £6,000-£15,000 - a rebuilt M274 engine (£2,500-£4,800) is usually well within the car's value. For the M274, a specialist replacement with an upgraded rebuilt unit is almost always better value than attempting to rebuild the original engine due to the wrist pin design flaw.

• W204 (2011-2014): rebuilt M271 viable for good condition cars
• W205 (2014-2018): rebuilt M274 usually justifies cost
• M274 wrist pin failure: replacement better than repair

Power loss in the C250 petrol depends on the engine. On M271 engines, timing chain stretch can cause cam timing drift, reducing power. On M274 engines, the wrist pin/piston seizure failure can cause misfires and power loss. Other causes include camshaft adjuster failure (M271) and oil leaks affecting engine performance. A diagnostic check with Mercedes STAR or compatible equipment is essential to identify the exact cause.

• M271 timing chain stretch - power loss + rattling
• M274 wrist pin failure - misfires and power loss
• Camshaft adjuster failure - rough running and power loss