Mercedes Benz CLK 200/220 CDI Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK Mercedes Benz CLK 200 CDI and CLK 220 CDI engine specialists. Compare prices on reconditioned, rebuilt and used OM646 2.1-litre turbo diesel engines - supply & fit available nationwide.
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3 Simple Steps to Finding the Right Replacement Engine
Clear information first, then the right engine and specialist for your exact vehicle.
Variant History
Mercedes CLK 200/220 CDI Engine History & Specs at a Glance
The Mercedes CLK 200 CDI and CLK 220 CDI arrived with the second-generation C209 CLK in the mid-2000s, powered by the OM646 2.1-litre four-cylinder common-rail turbodiesel. These engines offered a compelling blend of refinement and economy, making the CLK accessible to a wider audience than the petrol V6 and V8 variants.
2003
OM646 DE22 LA introduced in CLK 200 CDI (102-125 hp)
Mercedes CLK 200/220 CDI Engine Problems Repair Cost vs Replacement
The OM646 2.1-litre turbodiesel in the CLK 200 CDI and CLK 220 CDI is widely regarded as a durable and reliable workhorse - with properly maintained examples reaching 500,000 miles without major failures. However, like any diesel engine of its era, it has known weak points: injector seal leakage (the infamous "Black Death"), timing chain stretch, and turbocharger wear. Every rebuilt engine supplied through EnginesMarket includes upgraded components designed to address the original failure point - plus a minimum 12-month unlimited mileage warranty.
Injector seals fail, allowing unburnt diesel fuel and exhaust gases to escape past the seal. This creates a hard, tar-like carbon buildup around the injector seats - a condition commonly referred to as "Black Death." Symptoms include a chuffing noise from the engine bay, visible black residue around injectors, and rough running.
Repair options
Repair tier
Dealer price
Specialist price
Minor - Injector Seal Replacement
£400-£700
£250-£450
Intermediate - Injector Seat Re-cutting & Seal Replacement
£700-£1,200
£450-£800
Full Replacement - Rebuilt Engine
£3,500-£5,000
£2,200-£3,500
Our recommendation
Injector seal failure is the single most common issue on the OM646 engine. Don't ignore the tell-tale chuffing noise or black residue. Specialist injector seal replacement at £250-£450 is cost-effective and resolves the issue. However, if the engine has been run with leaking seals for an extended period, cylinder head damage may have occurred - in which case a rebuilt engine with new injectors and upgraded seals is the safer option.
The double roller timing chain can stretch over time, particularly with extended oil change intervals. Symptoms include rattling on cold start, rough running, and in severe cases, the chain jumping teeth and causing catastrophic valve/piston contact.
Repair options
Repair tier
Dealer price
Specialist price
Minor - Timing Chain Tensioner Replacement
£300-£500
£200-£350
Intermediate - Full Timing Chain & Sprocket Replacement
£1,200-£1,800
£800-£1,300
Full Replacement - Rebuilt Engine
£3,500-£5,000
£2,200-£3,500
Our recommendation
Rattling on cold start is the early warning sign. Don't ignore it - specialist timing chain replacement at £800-£1,300 resolves the issue if done promptly. The OM646 is otherwise a robust engine, and replacing the timing chain before failure can extend engine life significantly.
Turbocharger bearing wear and oil residue in the intake system can cause loss of boost pressure. Boost leaks from pipes between the turbo and inlet manifold are also common, triggering limp mode and power loss.
Repair options
Repair tier
Dealer price
Specialist price
Minor - Boost Leak Repair
£150-£300
£100-£200
Intermediate - Turbocharger Replacement
£1,200-£2,000
£700-£1,200
Full Replacement - Rebuilt Engine
£3,500-£5,000
£2,200-£3,500
Our recommendation
Loss of power and hissing noises are classic signs of a boost leak. Start with a simple inspection of intercooler pipes - often a £100-£200 fix. If the turbo itself has failed, specialist replacement at £700-£1,200 is cost-effective. However, if turbo debris has contaminated the oil system, full engine replacement is the only safe route.
Don't Let Engine Failure Write Off Your Mercedes CLK 200/220 CDI
Engine failure on a CLK 200 CDI or CLK 220 CDI doesn't have to mean the end of the car. Whether you're dealing with injector seal "Black Death," timing chain stretch, or turbocharger wear, EnginesMarket makes it simple to compare prices from trusted UK Mercedes CLK diesel specialists. Every rebuilt engine includes upgraded components designed to prevent the original failure from recurring, backed by a minimum 12-month unlimited mileage warranty. Compare prices today and get back on the road without the main dealer premium.
Everything Mercedes Benz CLK 200/220 CDI owners usually ask before choosing a rebuilt, reconditioned or used replacement engine.
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.
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
Comparing quotes for your Mercedes CLK 200 CDI or CLK 220 CDI engine replacement is free, quick and carries no obligation. Enter your registration above to get matched with vetted UK specialists who stock the exact OM646 engine for your CLK - whether you need a used unit, a reconditioned engine or a fully rebuilt motor with a 12-month warranty. Get back on the road with confidence, without the main dealer premium.
300+300+ CLK 200/220 CDI engines supplied through our network
12-Month12-Month Warranty on every rebuilt CLK 200/220 CDI engine
Compare quotes from trusted UK Mercedes Benz CLK 200/220 CDI engine specialists with warranty-backed rebuilt, reconditioned and used options nationwide.