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Select your model, chassis code and year. Get a matched engine code, real replacement cost data, and a repair-to-value verdict — instantly.
The Engine Compatibility Checker tells you which Mercedes engine code fits your specific vehicle, based on model, chassis and production year.
If you already know your engine code, use the Engine Code Decoder for full specification detail.
Three inputs produce your result. No registration, no VIN required for a basic match — though adding your VIN via our VIN Decoder narrows the result to a single engine variant where production-year overlaps exist.
Choose your Mercedes model (C-Class, E-Class, Sprinter, etc.) and the chassis code — W205, W212, X253, W906 — from the dropdown. If you are unsure of the chassis code, our Engine Code Guide explains where to find it on your vehicle.
Enter the production year and, if known, the badge designation (C220d, E350d, GLC300, etc.). This resolves mid-cycle engine changes — for example, the OM651 was replaced by the OM654 in W205 C-Class models from 2016 onward [EM-VERIFIED].
The checker returns the correct engine code, a supply-only cost range for used, reconditioned and rebuilt units [EM-QUOTE], and a repair-to-value flag based on our 70% scrap threshold framework.
Select your vehicle below. Results appear instantly beneath the form.
Your result will appear here.
Need help identifying your engine? Check the engine number location guide or use the OM vs M Series Identification reference to confirm whether your unit is a diesel (OM) or petrol (M) engine.
Each result contains three data points. Understanding them helps you make a confident replacement decision without a workshop visit.
The primary identifier Mercedes assigns to each engine family. For diesel engines, the prefix "OM" stands for Öl-Motor (oil engine); petrol units carry an "M" prefix. A single chassis code can span multiple engine codes across a production run — the W212 E-Class, for example, used both the OM651 four-cylinder and the OM642 V6 diesel depending on badge and year [EM-VERIFIED]. Our full fitment matrix maps every combination.
Supply-only pricing for three condition grades: used (lowest cost, highest risk), reconditioned (stripped, machined and rebuilt with new wearing components), and rebuilt (blueprinted to factory specification). All figures are drawn from actual supplier quotes routed through our platform [EM-QUOTE]. Labour for removal and refitting is separate — typically 8–16 hours depending on engine complexity [EM-QUOTE].
Our 70% threshold [PATTERN DATA] indicates whether replacement is financially sound for the typical host vehicle. If the lowest viable replacement cost exceeds approximately 70% of the vehicle's current market value, we flag it and recommend evaluating scrap value first using our Repair vs Replace Calculator. The three flags are:
Every figure in this checker traces back to verified sources. The compatibility mapping is built from manufacturer production data, cross-referenced against our internal enquiry database of 9,000+ real UK Mercedes engine replacement requests [EM-VERIFIED]. Cost ranges reflect actual supplier quotes sent to customers through our platform in 2025 [EM-QUOTE].
The Mercedes engines generating the highest enquiry volumes in our dataset are the OM651 (1,250 requests), the OM642 (880 requests), the OM654 (520 requests), the M276 (390 requests) and the M177 AMG V8 (370 requests) [EM-VERIFIED]. These five engines account for the majority of Mercedes-specific replacements we handle.
For full methodology and limitations, see our Data Verification page. For the annual ranking, see the Engine Failure Index 2026.
Yes, completely free with no email gate, no account creation and no usage limit. Results appear instantly. If you then want to compare quotes from vetted specialists, that routing is handled by EnginesMarket — but the checker itself is an independent editorial tool.
Yes. Select your model and production year first — the chassis dropdown will narrow automatically. If you want to confirm the chassis code physically, it appears on the VIN plate (visible at the base of the windscreen on most Mercedes models) and in your V5C logbook. Our Engine Code Guide walks through every location.
The checker returns the factory-original fitment. If a previous owner has swapped the engine, the physical unit may differ from the result shown. Confirm the actual engine code stamped on the block — the Engine Number Location reference shows where to look for each family.
Yes. AMG engines including the M156, M157, M177 and M178 are included in the database. However, AMG replacement costs are substantially higher — the M177 reconditioned supply alone runs £8,000–£14,000 [EM-QUOTE] — so the repair-to-value flag is especially important for AMG hosts. See our Most Expensive AMG Repairs analysis for context.
Once you have your engine code, compare used, reconditioned and rebuilt supply prices from vetted UK Mercedes engine specialists. Enter your registration and receive matched quotes within one working day.
Part of the Engine Finders network. Quotes routed via EnginesMarket.