Mercedes Benz CLK 230/320 Petrol Engine ReplacementCompare Prices & Get Quotes

A Mercedes CLK 230 Kompressor or CLK 320 replacement engine typically costs between £900 for a used unit and £2,500 for a fully rebuilt engine. Specialist fitting adds £400-£700.

• Used M111/M112 engines: £900-£1,800 depending on mileage and condition
• Reconditioned units: £1,200-£2,200 supply only
• Rebuilt units: £1,500-£2,500 with 12-month warranty
• Specialist fitting adds £400-£700; dealer labour is significantly higher
• 12-month warranty included on all rebuilt units through EnginesMarket

The M111 and M112 are two of Mercedes' most reliable engines from this era. The M112 V6 is particularly bulletproof, with no balance shaft issues (unlike the later M272). The M111 is also robust but suffers from timing chain rattle and supercharger clutch wear.

• M112 V6: widely regarded as one of Mercedes' most robust modern engines
• M111 four-cylinder: timing chain rattle on startup is the main warning sign
• Both engines can exceed 150,000-200,000 miles with proper maintenance
• Regular oil changes every 10,000 miles are critical for longevity

The M111 engine can develop a rattling noise on startup due to a worn timing chain tensioner or stretched chain. The camshaft adjuster can also fail, producing a clicking or rattling noise.

• Rattling on cold start is the classic warning sign
• Incorrect engine oil grade can accelerate chain wear
• Chain and tensioner replacement costs £800-£1,300 at a specialist
• Catch it early - a jumped chain can destroy the engine

Loss of power on the CLK 230 Kompressor is often due to supercharger clutch failure, split vacuum pipes, or a faulty recirculating air flap.

• Supercharger magnetic clutch wear causes loss of boost
• Split piping is a common and cheap fix
• Fault codes P1525 and P0443 can indicate supercharger issues
• Supercharger clutch replacement costs £250-£500 at a specialist

The M112 V6 engine is known for crankshaft position sensor failure, which causes the engine to stall when hot and take 5-15 minutes to restart. The sensor can fail due to heat cycling, with internal wiring breaking.

• Stalling when hot is the classic symptom
• No fault codes are often stored
• The sensor is located at the back of the engine and is tricky to access
• Specialist replacement costs £150-£300

On a CLK 230/320 worth £2,000-£6,000, specialist engine replacement at £1,500-£2,500 is worthwhile if the body and interior are in excellent condition. However, if the car has rust, electrical issues, or poor bodywork, consider scrapping it.

• CLK values have stabilised at "rock bottom" prices
• A clean, well-maintained CLK is worth saving
• Rebuilt M111/M112 engines cost £1,500-£2,500 supply only
• If the car has other major issues, replacement may not be cost-effective

Both are reliable, but the M112 V6 in the CLK 320 is widely considered the more robust engine. It has no balance shaft issues (unlike the later M272) and is known for exceptional longevity. The M111 four-cylinder is also reliable but has more age-related issues.

• M112 V6 (CLK 320): bulletproof, no major known weaknesses
• M111 four-cylinder (CLK 230): timing chain and supercharger clutch are common wear items
• Both engines can exceed 150,000-200,000 miles with proper maintenance
• The M112 is generally the more desirable engine for reliability