Mercedes Benz CLK 200/220 CDI Engine ReplacementCompare Prices & Get Quotes

A Mercedes CLK 200 or CLK 220 CDI replacement engine typically costs between £900 for a used unit and £2,500 for a fully rebuilt OM646 engine. Specialist fitting adds £400-£700.

• Used OM646 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

Yes - the OM646 is widely regarded as one of Mercedes' most durable diesel engines. With proper maintenance, examples have reached 500,000 miles without major failures. However, injector seal failure ("Black Death") is a known weakness, and timing chain stretch can occur on higher-mileage units.

• OM646 is a robust and durable workhorse
• Injector seal failure is the most common issue - catch it early
• Timing chain stretch can occur from 100,000 miles
• Regular oil and filter changes every 10,000 miles are critical for longevity

"Black Death" is the common term for injector seal failure on Mercedes CDI engines. When the seals fail, unburnt diesel and exhaust gases escape, creating a hard, tar-like carbon buildup around the injector seats.

• Symptoms: chuffing noise from engine bay, black residue around injectors
• If ignored, injectors can seize and cylinder head damage can occur
• Specialist seal replacement costs £250-£450
• Catch it early - the repair is far cheaper than engine replacement

Well-maintained OM646 engines regularly exceed 150,000-200,000 miles. With meticulous maintenance, some have reached 500,000 miles without major failures.

• OM646: 150k-200k+ miles with regular servicing
• Injector seal failure typically occurs from 80,000-150,000 miles
• Timing chain stretch risk from 100,000-200,000 miles
• Regular oil changes every 10,000 miles significantly extends life

Timing chain replacement on a CLK 200/220 CDI OM646 engine costs £800-£1,300 at a specialist or £1,200-£1,800 at a main dealer. This is preventative work. If the chain has already slipped, full engine replacement at £2,200-£3,500 is required.

• Specialist preventative chain replacement: £800-£1,300
• Dealer pricing for same work: £1,200-£1,800
• Rattling noise on cold start is the early warning sign
• Once timing jumps, valves contact pistons - engine is beyond repair

On a CLK 200/220 CDI worth £2,500-£5,000, 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 OM646 with upgraded seals and timing components costs £1,500-£2,500 supply only
• If the car has other major issues, replacement may not be cost-effective

Both use the same OM646 engine family. The CLK 200 CDI is a lower-power version (102-125 hp) while the CLK 220 CDI produces 150 hp. The difference is primarily in engine mapping and turbocharger specification, not mechanical hardware.

• Same engine block, cylinder head and bottom end
• Power difference is electronic mapping and turbo spec
• Reliability is identical between the two variants
• Replacement engines are interchangeable with correct ECU programming