Mercedes C200 & C220 CDI Engine Replacement — Compare Prices & Get Quotes
Get quotes today from trusted UK Mercedes C-Class specialists. Compare reconditioned, rebuilt and used OM611 and OM646 diesel engines — from the W202 to the W204 — supply & fit available nationwide.
The C200/C220 CDI THROUGH TIME — Era Map
Four generations. Four eras. One guide to reliability, costs and what really matters.
Era Note
Mercedes' first common-rail diesel in the C-Class. Fixed-vane turbo; injector seal failure ("black death") is a known pattern.
Why use this era map?
This table is the single source every other section on this page matches — Sections 2, 4 and 6 reference it rather than restating conflicting figures.
Mercedes C200/C220 CDI Engine Replacement Costs
Figures above reflect the OM611 and OM646 2.1-litre diesel engines. A replacement OM646.963 engine costs approximately £1,246 for a used unit in good condition, with reconditioned engines costing up to £1,495. Mercedes C-Class engine replacements typically cost £3,500 or more, with total costs (including labour) potentially exceeding £5,000. Main dealer new engines are no longer available.
Labour estimate: Fitting a C-Class CDI engine typically takes 10–14 hours at £70–£100/hr (independent) or £120–£180/hr (London/SE dealer).
Common Problems
1. Diesel Injector Seal Failure ("Black Death") — OM611 & OM646
Symptoms: Chuffing or ticking noise from the engine bay, smell of exhaust gases inside the cabin, soot buildup around injectors, rough running, loss of power, engine warning light.
Typical mileage: 60,000–120,000 miles
Repair cost: £400–£1,200 (injector seal replacement — copper seals + cleaning)【PLACEHOLDER — confirm vs cost sheet】
Replacement cost: £2,500–£6,500 (if left untreated and damages the cylinder head)
🟠 Check - book inspection urgentlyOur recommendation:
"Black death" is the most notorious issue on Mercedes OM611 and OM646 diesel engines. When injector seals fail, unburnt diesel and exhaust gases escape past the injector, causing carbon buildup around the injector. If left untreated, the injector can seize in the cylinder head, requiring cylinder head removal or replacement. If you notice a chuffing noise or smell of exhaust gases inside the cabin, have the injector seals inspected immediately. Replacement of the copper seals and cleaning of carbon deposits is the solution.
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C200/C220 CDI — Repair, Buy, or Replace?
Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.
Can It Be Repaired?
Buying This C-Class CDI? Check These First
Buy If
- Full Mercedes service history with evidence of regular oil changes using MB 229.5 or 229.51 spec oil
- Injector seals replaced or inspected within the last 40,000 miles
- No cold-start rattle — a quiet startup suggests healthy timing chain
- Post-2003 OM646 preferred over early OM611 (more durable)
Avoid If
- Chuffing noise or exhaust smell in the cabin (injector seal failure)
- Cold-start rattle with no timing chain history
- Loss of power or limp mode with no turbo diagnosis
- Poor service history — these engines are durable but need good maintenance
Closing Verdict
The C200 and C220 CDI badges represent Mercedes' first common-rail diesel engines in the C-Class — a significant technological leap that delivered excellent fuel economy and refined performance. The OM646 in particular is widely regarded as a "very durable engine". However, these engines have known weak points: injector seal failure ("black death") is the most notorious; turbocharger issues and timing chain tensioner wear are also common. These are well-understood and fixable issues, but they demand attention and budget. Buy on documented history, not on faith. A well-maintained C-Class CDI is a £3,000–£8,000 used premium saloon; a neglected one is a £4,000 engine replacement waiting to happen.
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Get real quotes from vetted UK specialists and make the right call for your 320d.
→ Compare C-Class diesel engine prices before you buy
Buying Checklist
Before you buy a used Mercedes C200 or C220 CDI (or before you commit to an engine replacement), check these:
Cold Start — Listen for rattling (timing chain tensioner warning) or chuffing (injector seal warning)
Service History — including which engine era (OM611 or OM646) and confirmed oil-change intervals using MB 229.5/229.51 spec oil
Injector Seal Check — Any history of injector seal replacement? Check for soot around injectors
Turbo Check — Any loss of power, limp mode, or black smoke? (turbo vanes or actuator warning)
DPF Check (W203/W204) — Any DPF warning lights or regeneration issues? (urban-driven vehicles are high risk)
Smoke Check — Black smoke can indicate turbo or injector issues; white smoke can indicate coolant issues
Engine Warning Light — Have codes been read? Any unresolved injector, turbo, or timing-related codes?
MOT History — Check for emissions-related failures
Buy smart. Drive with confidence.
A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.
Engine Codes
This table's rows match Section 1B's Era Map exactly.
OM611 (2.1L 4-cyl CDI)
Technical Specs
OM611 / OM646→ Compare C-Class diesel engine prices for your Mercedes
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Market Intelligence
Most Common Failure
Diesel injector seal failure ("black death") — the most notorious issue on OM611 and OM646 engines
Average Enquiry Mileage
80,000
–120,000 miles
[PATTERN DATA]
Average Replacement Cost
£2,800
–£5,000 reconditioned, supply only
[PLACEHOLDER — confirm vs cost sheet]
Most Requested Engine Code
OM646 (C220 CDI)
[PATTERN DATA]
Peak Enquiry Season
Winter — cold starts expose timing chain and injector issues【PATTERN DATA】
Regional Demand
PATTERN DATA
Regional Demand Breakdown
Frequently Asked Questions
All prices are indicative UK market ranges based on historical quote data from our network of engine specialists. Actual costs vary by variant, engine code, damage severity and workshop location. Use our free comparison tool to get tailored quotes. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited-mileage warranty — always confirm terms with your chosen supplier.
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every garage and engine rebuilder in our network is vetted, rated and reviewed by real C-Class owners, as part of the Engine Finders network, across the entire OM611 and OM646 era — from the W202 to the W204.
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see prices, warranty terms and supply & fit options side-by-side before you commit, across every C-Class that left the factory with the 2.1-litre CDI engine.
UK Engine Replacement Services for C-Class Diesel
supply-only or full supply & fit available nationwide, covering the full W202, W203 and W204 production runs — and we're vetted across every era of this badge.
Find the best Mercedes C200 or C220 CDI engine replacement UK drivers rely on. Compare prices from trusted specialists on EnginesMarket today and get your C-Class back on the road with confidence.
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No hidden fees
No Obligation
Get quotes with zero pressure
UK Specialists
20+ vetted experts
12-Month Warranty
As standard
Nationwide Delivery
Supply & fit available