Mercedes B‑Class B200 CDI / B200d Engine Replacement — Compare Prices & Get Quotes
Get quotes today from trusted UK Mercedes specialists. Compare reconditioned, rebuilt and used OM651 and OM654q diesel engines for the B‑Class B200 CDI and B200d — the refined, efficient diesel that powers Mercedes' premium compact MPV. Supply & fit available nationwide.
Mercedes B‑Class B200 CDI / B200d — Which Engine Does Your Car Actually Have?
Four generations. Four eras. One guide to reliability, costs and what really matters.
Era Note
136 PS, 300 Nm — timing chain stretch is the defining weakness
Why use this era map?
This table is the single source every other section on this page must match. Sections 2, 4, and 6 reference it rather than restating conflicting figures.
Mercedes B‑Class B200 CDI / B200d Engine Replacement Costs
Figures above reflect the B200 CDI/B200d pricing. A replacement OM651.901 engine costs on average £2,793 in good condition, with new or reconditioned units costing up to £3,436. Reconditioned engines typically range from £1,200–£2,200, with total installed cost around £1,800–£2,800. As a front‑wheel‑drive vehicle with a transverse engine, labour costs are slightly higher than for rear‑wheel‑drive models.
Labour estimate: Fitting a B‑Class CDI engine typically takes 10‑14 hours at £75‑£110/hr (independent Mercedes specialist). The transverse engine mounting and front‑wheel‑drive layout add complexity.
Common Problems
1. OM651 Timing Chain Stretch (W246, 2012–2018)
Symptoms: Rattling or clattering noise from the engine for 2‑5 seconds after cold start, metallic ticking, engine warning light, rough running, loss of power. The timing chain is at the rear of the engine, making access labour‑intensive.
Typical mileage: 60,000–100,000 miles — many owners report noise around 90,000 miles.
Repair cost: £1,200–£2,500 [PLACEHOLDER] (timing chain, tensioner, and guide replacement — engine or gearbox removal required).
Replacement cost: £2,793–£3,800 [PLACEHOLDER] (if chain snaps and damages the engine).
🔴 Immediate - if you hear rattling on cold start, book an inspection immediately.Our recommendation:
The OM651 timing chain is the defining weakness of the W246 B200 CDI. The chain is mounted at the rear of the engine, making replacement a very big job that likely requires engine or gearbox removal. The stop‑start system causes additional stress to the chain. A £1,200–£2,500 preventative chain replacement is far cheaper than a £2,793–£3,800 engine replacement. At the first sign of cold‑start rattle, have the timing system inspected immediately. Use a genuine Mercedes tensioner — not aftermarket.
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Mercedes B‑Class B200 CDI / B200d — 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 Mercedes B‑Class B200 CDI / B200d? Check These First
Buy If
- Full Mercedes service history with regular oil changes (every 8,000–10,000 miles)
- W246 (OM651): Timing chain quiet — no rattling on cold start
- W247 (OM654q): Recall work verified as completed — cylinder head bolt issue is critical
- W246: 7G‑DCT transmission serviced — fluid changes are essential
- A well‑maintained example — the OM651 is durable with proper care
Avoid If
- W246: Any sign of timing chain rattle on cold start — this is the defining weakness
- W247: No evidence of recall completion — cylinder head bolt failure is a safety issue
- W246: Any sign of jerky gear changes — 7G‑DCT issues can be expensive
- Poor service history — these engines are intolerant of neglect
Closing Verdict
The Mercedes B‑Class B200 CDI and B200d are efficient and refined diesel‑powered MPVs. The W246 (2012–2018) with the OM651 engine is a durable powerplant with a well‑documented Achilles heel: rear‑mounted timing chain stretch. The W247 (2018–present) with the OM654q engine is a newer design with improved power and efficiency, but a cylinder head bolt recall has been issued. Buy on service history above all else — a vehicle with documented timing chain maintenance (W246) or recall completion (W247) is a safe bet; a neglected example can be expensive to repair.
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Buying Checklist
Before you buy a used Mercedes B‑Class B200 CDI / B200d (or before you commit to an engine replacement), check these:
1. Cold Start — Any rattling for 2‑5 seconds? (OM651 timing chain warning — stop immediately)
2. Service History — Regular oil changes (every 8,000‑10,000 miles) — this is non‑negotiable
3. Timing Chain History — W246 (OM651): Has the chain been inspected or replaced?
4. Recall Status — W247 (OM654q): Cylinder head bolt recall completed? This is critical
5. Transmission — W246: Any jerky shifts, shuddering, or delayed engagement? (7G‑DCT warning)
6. DPF Health — Has the vehicle done regular longer runs? (short trips kill DPFs)
7. Turbo Health — Any whining noise, turbo lag, or smoke? (turbo warning)
8. MOT History — Check for emissions‑related failures or any advisory notes
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.
OM651.901 (2.1L I4 Turbo Diesel)
Technical Specs
OM654q — 2.0L 4‑Cylinder Turbodiesel→ Compare B‑Class B200 CDI engine prices for your Mercedes
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Market Intelligence
Most Common Failure
OM651 timing chain stretch (W246) — the defining weakness of the engine
Average Enquiry Mileage
60,000
–90,000 miles
[PATTERN DATA]
Average Replacement Cost
£2,793
reconditioned, supply only
[PLACEHOLDER]
Most Requested Engine Code
OM651.901 — the W246 is more common on the used market
[PATTERN DATA]
Peak Enquiry Season
Autumn/Winter — cold starts expose timing chain wear
[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.
Why UK Mercedes B‑Class B200 CDI / B200d Owners Trust MercedesEngine.uk
Trusted B200 CDI Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real B‑Class owners, as part of the Engine Finders network, covering both the OM651 and OM654q diesel engines across two generations.
Compare B200 CDI Engine Replacement Companies
see prices, warranty terms and supply & fit options side‑by‑side before you commit, with specialists who understand the OM651's timing chain vulnerabilities, the OM654q's cylinder head bolt recall, and the importance of regular oil changes.
UK Engine Replacement Services for the B‑Class
supply‑only or full supply & fit available nationwide, covering the W246 and W247 generations of the B200 CDI and B200d, with specialist knowledge of Mercedes' compact diesel engines.
Find the best Mercedes B‑Class B200 CDI / B200d engine replacement UK drivers rely on. Compare prices from trusted specialists on EnginesMarket today and get 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