Mercedes‑Benz E‑Class C238 Engines — The Complete UK Guide
Every engine fitted to the C238 coupé — from the 2.0‑litre M274 petrol to the 3.0‑litre straight‑six M256 in the E 450 and AMG E 53. Real UK replacement costs, honest reliability data, and the coupe‑specific running costs that define this generation. Backed by real UK C238 enquiries in 2025 [MB‑VERIFIED].
Explore C238 Engines
Mercedes‑Benz E‑Class C238 Engine Codes — The Complete Database
Every engine fitted to the C238 coupé specifically — spanning pre‑facelift (2017–2020) and facelift (2020–2023) powertrains.
Overview
Mercedes‑Benz E‑Class C238 — Overview
The C238 is the coupé bodystyle of the tenth‑generation Mercedes‑Benz E‑Class, launched in spring 2017 as the successor to the C207.
It marked a significant shift: unlike its predecessor and the CLK before it, the C238 shared its proper executive‑sized platform with the W213 E‑Class saloon — making it substantially larger and more sophisticated. A major 2020 facelift brought mild‑hybrid technology to the petrol line‑up, replacing the V6 with the M256 straight‑six and introducing the OM654 M diesel with integrated starter‑generator. Every C238 is powered by a longitudinally‑mounted four or six‑cylinder engine, driving the rear wheels or 4MATIC all‑wheel drive.
Key Facts
Platform
Mercedes‑Benz MRA (Modular Rear Architecture)
Predecessor
C207
Successor
C236 (CLE)
Sibling body styles in this generation
W213 Saloon, S213 Estate, A238 Cabriolet
Market Intelligence
The E‑Class range (W213/S213/C238/A238 combined) generated real UK engine enquiries in 2025 [MB‑VERIFIED], with the OM654 diesel and M256 petrol commanding the strongest specialist interest.
Best & Worst Engines
Best Diesel Overall
OM656 2.9‑litre straight‑six diesel (E 400 d, 330–340hp)
“The most powerful diesel six Mercedes has ever built — 340hp and 700Nm from a 2.9‑litre straight‑six. Smooth, effortless, and fundamentally robust, with none of the AdBlue system issues that plague the OM654. The OM656 is a genuine modern classic in the making.”
Who it's for: buyers who want diesel refinement and effortless torque without the four‑cylinder's compromises.
Best Petrol Overall
M256 3.0‑litre straight‑six (E 450, 367hp)
“Mercedes' return to the straight‑six — 367hp, 500Nm, and a 48V mild‑hybrid system that adds 22hp and 250Nm of electric boost. Smooth, responsive, and far more refined than the V6 it replaced. Cooling system maintenance is the only real demand.”
Who it's for: buyers who want straight‑six refinement and genuine performance.
Highest Risk
M274 2.0‑litre turbo (E 200, 184hp / E 300, 245hp)
“The pre‑facelift four‑cylinder turbo is the most contentious engine in the range — timing chain stretch is a documented issue on higher‑mileage examples, and it lacks the refinement of the later M264 or the sixes. Avoid without documented chain history.”
Who it's for: buyers on a tight budget who prioritise running costs over refinement.
Most Expensive Failure
M256.930 (AMG E 53, 435hp)
“The highest‑strung M256 tune — 435hp from a 3.0‑litre straight‑six with 48V mild‑hybrid. Tight engine bay packaging makes even sensor replacement labour‑intensive, and cooling system integrity is critical on hard‑driven cars.”
Who it's for: AMG buyers with deep pockets and a trusted specialist.
Best Value
OM654 2.0‑litre diesel (E 220 d, 163–194hp)
“The volume diesel in the C238 range — 194hp and 400Nm deliver strong real‑world performance, and the OM654 is a proven modern diesel with AdBlue system maintenance as its only real cost. Lower running costs than the six‑cylinder diesel, with 90% of the torque.”
Who it's for: buyers who want diesel economy without the six‑cylinder's purchase premium.
Most Overlooked
M264 2.0‑litre mild‑hybrid (E 300 EQ Boost, 258hp)
“The facelift replacement for the M274 — 258hp, 48V mild‑hybrid, and none of the M274's timing chain concerns. It sits in a sweet spot between the four and the six, offering genuine performance without the M256's running costs. Often overlooked in favour of the sixes.”
Who it's for: buyers who want modern petrol efficiency without the six‑cylinder's fuel consumption.
Mercedes‑Benz E‑Class C238 — Ownership Economics
The C238 rule
A £3,000–£5,000 OM654 recon against a £15,000–£25,000 C238 sits at 12–33% of the car's value — well inside the 70% Mercedes‑Benz threshold. Against a £10,000 high‑mileage example, the same recon reaches 30–50% — still viable, but a significant proportion of the car's residual value. Value the car and its service history first.
Common Problems
C238 Engine Replacement Costs — By Engine and Condition
Core Variants
Core Variants
Diesel Variants
Scope note: All variants listed are C238 coupé only. W213 Saloon, S213 Estate and A238 Cabriolet share most of these engines but are covered on their own Generation Pages, since fitment and production years vary by body style.
Market Intelligence
Most Requested E90 Engines (2025)
Most Requested E90 Variants
Average E90 Replacement Cost
Most Common E90 Failures
FAQ
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Trusted C238 Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real C238 owners, as part of the Engine Finders network.
Compare C238 Engine Replacement Companies
see prices, warranty terms and supply‑and‑fit options side‑by‑side before you commit.
UK Engine Replacement Services for C238
covering every variant from E 200 to AMG E 53, with supply‑only or full supply‑and‑fit available nationwide.
Find the best Mercedes‑Benz E‑Class C238 engine replacement UK drivers rely on. Compare real prices from trusted specialists on EnginesMarket today and get back on the road with confidence.
