Question 1

How much does an M274 engine replacement cost?

Accepted Answer

A reconditioned M274 typically costs £2,200–£3,800 supply only, varying by specific variant and power output. Fitting adds £800–£1,200 depending on labour rates. Use our calculator for a figure specific to your car.

Question 2

Is the Mercedes M274 a reliable engine?

Accepted Answer

The M274 is rated 3.5★ out of 5 — it won Ward's 10 Best Engines in 2017 and is generally refined and efficient, but camshaft adjuster wear and timing chain tensioner issues are well-documented, especially from 60,000 miles.

Question 3

What is the most common M274 failure?

Accepted Answer

The most common failure is camshaft adjuster (phaser) wear, caused by a design anomaly. Symptoms include cold-start rattle, Check Engine Light, and rough running. Repair requires replacing both camshafts — a £1,000+ job at an independent specialist.

Question 4

Which Mercedes models use the M274?

Accepted Answer

The M274 powered a wide range of Mercedes models including the A-Class (W176), CLA-Class (C117), C-Class (W205), E-Class (W212/W213), GLA-Class (X156), GLC-Class (X253), and SLC/SLK-Class (R172), plus the Infiniti Q50 and Q60.

Question 5

Is the Mercedes M274 the same as the Infiniti version?

Accepted Answer

Yes — Infiniti used the M274 in the Q50 and Q60 under license from Mercedes-Benz. The engine is mechanically identical, though ECU tuning differs slightly between brands. The same camshaft and timing chain issues affect both.

Mercedes-Benz M274 Engine – Specs, Reliability & Replacement Cost

Jaguar Mercedes-Benz M274 Engine Overview

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Jaguar Engine Engine Price Guide

Jaguar Engine Engine Price Guide

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