Mercedes Benz SLK 250/350 Engine Replacement Compare Prices & Get Quotes

Short summary: A rebuilt M271 engine for the SLK 250 costs £2,200-£3,500 supply-only; a rebuilt M272 engine for the R171 SLK 350 costs £2,800-£4,200; a rebuilt M276 engine for the R172 SLK 350 costs £3,200-£5,200. Fitting adds £800-£1,500 depending on complexity - V6 work requires specialist knowledge.

• SLK 250 (M271.861): rebuilt unit £2,200-£3,500; used engine from £1,000
• SLK 350 (M272.963/969): rebuilt unit £2,800-£4,200; used engine from £1,200
• SLK 350 (M276.956): rebuilt unit £3,200-£5,200; used engine from £1,500
• M271 timing chain replacement: £1,200-£1,800 at specialist
• M272 balance shaft replacement: £2,100-£2,900 at specialist

Short summary: A rattling noise on cold start is the classic warning sign on the M271 engine. The timing chain can stretch over time, especially on earlier models, and the plastic timing chain guides can wear down.

• Rattling noise on cold start lasting 1-3 seconds - earliest warning
• Engine misfires or rough idling
• Check engine light with timing correlation codes
• Poor fuel economy and loss of power
• If caught early, timing chain replacement costs £1,200-£1,800 at specialist

Short summary: Check engine light, rough running, and valve train clatter are the classic warning signs on the M272 engine. The balance shaft gear failure is a known catastrophic issue on early M272 V6 engines.

• Check engine light with P1200/P1208 fault codes
• Valve train clatter or metallic noise
• Rough running or misfiring
• If caught early, balance shaft replacement costs £2,100-£2,900 at specialist

Short summary: The M271 turbo four-cylinder is generally reliable but the timing chain is a known weakness. The M272 V6 is smooth and refined but early units suffer from balance shaft issues. The M276 V6 largely resolves the balance shaft problems of its predecessor but can develop timing chain tensioner wear.

• M271 timing chain stretch is the main concern - early intervention is key
• M272 balance shaft failure affects pre-2008 engines - check engine number
• M276 is more reliable than M272 but tensioner wear is possible
• Regular oil changes with MB 229.5 spec oil are essential for all engines

Short summary: Properly maintained M271 engines routinely reach 150,000-200,000 miles before major work. The M272 can achieve similar mileage but may require balance shaft attention between 50,000-90,000 miles. The M276 is too new for definitive long-term data but is showing good durability.

• M271 (SLK 250): 150,000-200,000 miles with regular servicing
• M272 (SLK 350): 150,000-200,000 miles - balance shaft inspection from 50k miles
• M276 (SLK 350): too early for definitive data - tensioner issues from 60k miles
• Service interval is 10,000 miles or 12 months - use Mercedes-spec MB 229.5 oil

Short summary: Yes, if the SLK is otherwise in good condition with no rust or major transmission faults. A rebuilt M271 costs £2,200-£3,500 - far less than replacing a £6,000-£18,000 vehicle. SLK values remain strong for well-maintained examples, making engine replacement a worthwhile investment.

• SLK 250 values: £6,000-£15,000 depending on condition and mileage
• SLK 350 values: £4,000-£18,000 depending on generation and condition
• Rebuilt engine with upgraded components fixes original weak points
• Supply & fit typically £3,000-£6,700 depending on engine code
• New engine includes 12-month unlimited mileage warranty