Mercedes Benz GLC Class 250/300 Petrol Engine Replacement Compare Prices & Get Quotes

Short summary: A rebuilt M274 engine for the GLC 250 costs £2,500-£4,000 supply-only; a rebuilt M264 engine for the GLC 300 costs £3,200-£4,500 supply-only. Fitting adds £800-£1,500 depending on complexity.

• GLC 250 (M274.920): rebuilt unit £2,500-£4,000; used engine from £1,200
• GLC 300 (M264.920): rebuilt unit £3,200-£4,500; used engine from £1,500
• M274 timing chain kit (labour only): £1,200-£1,800 at specialist
• Price depends on engine code, year, mileage, and supplier warranty length

Short summary: A 1-3 second rattling noise on cold start is the classic warning - most common on M274 petrol engines (GLC 250/300, 2015-2019). Ignoring it risks engine seizure and £5,000+ repair bills.

• Cold start rattle that disappears after oil pressure builds - earliest warning sign
• Check engine light with cam/crank correlation codes (P0016/P0017)
• Metallic swarf in engine oil indicates chain guides wearing away
• Preventative tensioner replacement costs £300-500 - full chain kit £1,200-1,800

Short summary: The M264 is a modern, efficient engine with strong performance, but has a known cylinder head exhaust valve failure that can occur as early as 40,000 miles - causing misfire and sudden power loss. The 48V mild-hybrid system also adds complexity.

• Cylinder head / exhaust valve failure reported from 40,000 miles - misfire, power loss
• 48V BSG (belt-driven starter-generator) can fail - replacement is costly
• Some cylinder head replacements have been covered under warranty or goodwill
• Well-maintained M264 engines typically exceed 150,000 miles

Short summary: Properly maintained M274 petrol engines routinely reach 150,000-200,000 miles before major work. The M264 is too new for definitive long-term data, but early indications suggest similar longevity with proper maintenance - assuming the cylinder head issue is addressed.

• M274 (250/300, 2015-2019): 150,000-200,000 miles with regular servicing
• M264 (300, 2019-2025): too early for definitive data - head failures reported from 40k miles
• Service interval is 10,000 miles or 12 months - use Mercedes-spec oil (MB 229.5)
• Late oil changes are the #1 cause of preventable failure on both engines

Short summary: Yes, if the GLC is otherwise in good condition with no rust or major electrical faults. A rebuilt M274 costs £2,500-£4,000 - far less than replacing a £14,000-£38,000 vehicle. The GLC's strong residual values make engine replacement financially justifiable.

• GLC 250/300 values: £14,000-£38,000 depending on year, mileage and condition
• Rebuilt engine with upgraded components fixes original weak points
• Supply & fit typically £3,500-£6,000 depending on engine code
• New engine includes 12-month unlimited mileage warranty

Short summary: Mercedes-Benz specifies MB 229.5 high-performance oil for the M274 and M264 - typically 5W-30 or 5W-40 fully synthetic. The M274 requires approximately 6.5 litres; the M264 requires approximately 6.1-7.0 litres.

• M274 (250/300, 2015-2019): MB 229.5 5W-30 or 5W-40 - high-spec synthetic only
• M264 (300, 2019-2025): MB 229.51 or 229.52 - low-SAPS for emissions system protection
• Never use non-approved oil - destroys timing chain tensioners and hydraulic lifters
• Change every 10,000 miles or 12 months - stretched intervals cause timing chain wear