Ownership Economics · Cost Data

Mercedes Replacement Cost By Engine Code

Every Mercedes engine has a different replacement cost. Here are the real 2025 UK figures for OM651, OM642, OM654, M276, M177 and more – supply-only and fitted, with labour hours and 2025 enquiry volumes.

Mercedes engine cutaway showing internal components, representing replacement cost by engine code
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24,650
Real UK Enquiries
Analysed
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15+
Vetted Mercedes
Specialists
⚖️
70%
Our Repair-to-Value
Threshold
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Part of
Engine Finders
Network

The short answer: Mercedes engine replacement costs vary widely by engine code. The cheapest is the OM651 at £2,800–£4,800 supply-only, while the most expensive is the M177 AMG V8 at £8,000–£14,000. Fitted costs range from £3,500 for an OM651 to £15,400+ for an M177 [EM-QUOTE].

Next step: find your engine code in the table below, then use the Repair vs Replace Calculator to run your own numbers.

Mercedes Engine Replacement Costs — Ranked by Engine Code

The definitive ranking of Mercedes engine replacement costs in 2025, based on real UK supplier quotes and enquiry data [EM-QUOTE]. All figures are supply-only.

RankEngine CodeTypeRecon SupplyUsed SupplyRebuilt SupplyLabour HoursEnquiries 2025
1 OM651 2.1 4‑cyl diesel £2,800–£4,800 £1,500–£2,800 £4,000–£6,000 8–12 hrs 1,250 [EM-VERIFIED]
2 OM654 2.0 4‑cyl diesel £3,000–£5,000 £1,800–£3,200 £4,200–£6,500 8–12 hrs 520 [EM-VERIFIED]
3 OM642 3.0 V6 diesel £3,200–£5,500 £1,800–£3,200 £4,500–£7,000 10–14 hrs 880 [EM-VERIFIED]
4 M276 3.5 V6 petrol £3,800–£6,500 £2,000–£3,800 £5,500–£8,500 12–16 hrs 390 [EM-VERIFIED]
5 M278 4.7 V8 petrol £5,000–£8,000 £2,500–£4,500 £7,000–£10,000 14–18 hrs
6 M157 5.5 V8 AMG £6,000–£10,000 £3,500–£6,000 £8,000–£14,000 16–22 hrs 410 [EM-VERIFIED]
7 M177 4.0 V8 AMG £8,000–£14,000 £4,000–£8,000 £12,000–£18,000 16–22 hrs 370 [EM-VERIFIED]
8 M275/M279 5.5/6.0 V12 £10,000–£20,000+ £6,000–£12,000+ £15,000–£25,000+ 20–30 hrs

[EM-QUOTE] prices are supply-only; fitted costs include indie labour at £65/hr. Main dealer costs are 40–60% higher. For a full breakdown of each engine, visit its Knowledge Centre page.

OM651 — The Cheapest Mercedes Engine to Replace

The OM651 2.1‑litre 4‑cylinder diesel is the most‑enquired Mercedes engine in our 2025 data (1,250 requests [EM-VERIFIED]) – and the cheapest to replace.

Typical Applications

C‑Class (W204, W205), E‑Class (W211, W212), GLC (X253), GLA (X156), GLK (X204), A‑Class (W176), B‑Class (W246), Sprinter, Vito

Replacement Costs

Recon: £2,800–£4,800 supply [EM-QUOTE]
Used: £1,500–£2,800 supply [EM-QUOTE]
Fitted: £3,500–£5,600

Labour: 8–12 hours. The OM651 is widely available and supported – replacement is almost always financially viable on any Mercedes worth more than £5,000.

OM651 Knowledge Centre →

OM654 — The Modern Diesel

The OM654 2.0‑litre 4‑cylinder diesel is the successor to the OM651, fitted to newer C‑Class (W206), E‑Class (W213/W214), GLC (X254) and GLE (V167).

Typical Applications

W205, W206, W213, W214, X253, X254, V167, C167

Replacement Costs

Recon: £3,000–£5,000 supply [EM-QUOTE]
Used: £1,800–£3,200 supply [EM-QUOTE]
Fitted: £3,700–£5,800

Labour: 8–12 hours. The OM654 is modern and well‑supported – replacement is trivially viable on almost any Mercedes worth more than £6,000.

OM654 Knowledge Centre →

OM642 — The V6 Diesel Workhorse

The OM642 3.0‑litre V6 diesel is the second most‑enquired Mercedes engine (880 requests [EM-VERIFIED]). Fitted to E‑Class, GLE, GL, Sprinter and more, it's more expensive to replace than the OM651 but still very common.

Typical Applications

E‑Class (W211, W212, W213), GLE (W166, V167), GL (X164, X166), Sprinter (W906, W907), ML (W164, W166)

Replacement Costs

Recon: £3,200–£5,500 supply [EM-QUOTE]
Used: £1,800–£3,200 supply [EM-QUOTE]
Fitted: £4,000–£6,400

Labour: 10–14 hours. The OM642 is well‑supported but the V6 layout adds labour time. Replacement is usually viable on any Mercedes worth more than £7,000.

OM642 Knowledge Centre →

M276 — The V6 Petrol

The M276 3.5‑litre V6 petrol is found in the E‑Class, CLS, GLE and SL – and is the most expensive non‑AMG V6 to replace.

Typical Applications

E‑Class (W212, W213), CLS (C218, C257), GLE (W166), SL (R231)

Replacement Costs

Recon: £3,800–£6,500 supply [EM-QUOTE]
Used: £2,000–£3,800 supply [EM-QUOTE]
Fitted: £4,600–£7,500

Labour: 12–16 hours. The M276 is a complex V6 – timing chain issues are common. Replacement is viable on most cars worth more than £10,000.

M276 Knowledge Centre →

M177 — The AMG V8

The M177 4.0‑litre V8 is the most expensive non‑V12 Mercedes engine to replace – and one of the most costly AMG repairs. Fitted to the AMG GT, C63, E63 and S63.

Typical Applications

AMG GT (C190/R190), C63 (W205, W206), E63 (W213), S63 (W222, W223), G63

Replacement Costs

Recon: £8,000–£14,000 supply [EM-QUOTE]
Used: £4,000–£8,000 supply [EM-QUOTE]
Fitted: £9,000–£15,400

Labour: 16–22 hours. The M177 is a complex hot‑vee V8 – cylinder scoring is a known risk. Replacement is usually viable on any AMG worth more than £20,000.

M177 Knowledge Centre →

The Verdict – Which Engine Costs the Most?

The M177 AMG V8 is the most expensive standard Mercedes engine to replace, but the V12 M275/M279 is the costliest overall. Here's the summary.

💰 Cheapest: OM651

At £2,800–£4,800 supply, the OM651 is the cheapest Mercedes engine to replace. It's the most‑enquired engine for a reason – parts are everywhere, specialists know it inside out, and it's affordable to re‑engine.

🏆 Most Expensive (Non‑V12): M177

At £8,000–£14,000 supply, the M177 AMG V8 is the most expensive non‑V12 Mercedes engine to replace. On a £40,000+ AMG GT, it's still financially viable – but on a £20,000 C63, it's borderline.

🔴 Most Expensive Overall: V12 M275/M279

At £10,000–£20,000+ supply, V12 engines are the most expensive to replace. On a £10,000 S600, a £15,000 V12 replacement is 150% of the car's value – a clear write‑off. Only consider if your car is worth £30,000+.

For the full cost breakdown of every Mercedes engine, visit the Engine Knowledge Centre or use the Repair vs Replace Calculator.

Frequently Asked Questions

Which Mercedes engine is cheapest to replace?

The OM651 2.1‑litre diesel is the cheapest – recon supply costs £2,800–£4,800. It's the most‑enquired engine in our data (1,250 requests in 2025) and parts are widely available.

How much does a Mercedes OM651 engine cost?

Supply‑only, a reconditioned OM651 costs £2,800–£4,800. Fitted, expect £3,500–£5,600. Used units are cheaper at £1,500–£2,800 but carry more risk.

Which Mercedes engine is most expensive to replace?

The V12 M275/M279 is the most expensive – recon supply costs £10,000–£20,000+. The M177 AMG V8 is the most expensive non‑V12 at £8,000–£14,000 supply.

How much does an AMG engine replacement cost?

An M177 AMG V8 recon costs £8,000–£14,000 supply; fitted, £9,000–£15,400. An M157 recon costs £6,000–£10,000 supply; fitted, £7,000–£11,400.

What is the 70% rule for Mercedes engine replacement?

The 70% rule: if the full fitted repair cost exceeds 70% of your Mercedes's current market value, the honest verdict is to scrap or sell for parts. Always apply this to your individual engine and vehicle.

How many Mercedes engine enquiries did you receive in 2025?

Mercedes accounted for over 5,000 of our 24,650 total engine enquiries in 2025, with OM651 alone generating 1,250 requests [EM-VERIFIED].

Genuine Enquiry DataBuilt from 24,650 real 2025 UK engine enquiries, including over 5,000 Mercedes-specific records.

Fully Disclosed MethodWe publish the exact costs for every engine – no guesswork.

15+ Vetted Mercedes SpecialistsEvery recommendation routes to a specialist who works on these engines daily.

100% IndependentNo sponsors, no manufacturer influence – we tell you the real costs.

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