Mercedes-Benz OM656 3.0 Inline-6 Diesel Engine
Used & Reconditioned for Sale
350d, 400d, 3.0 CDI, D300/D350-era
Displacement
Fuel
Production
Fits Mercedes-Benz E-Class W213, S-Class W222/W223, GLE/GLS W167/X167 and more — also known as 350d, 400d. Verified fitment, fixed prices, UK delivery.
Displacement
Fuel
Production
Configuration
Applications
Verified Fitment
Checked by registration
12-Month Warranty
On reconditioned units
UK Nationwide Delivery
2-4 working days
14-Day Returns
Uninstalled, full refund
Buy a OM656 Engine for Your Vehicle
This engine family serves 5 distinct Mercedes-Benz applications across E-Class, CLS, S-Class, GLE/GLS, and G-Class. Each application is configured and priced for its specific vehicle — used units available with warranty.
Application availability is being added. Contact us to confirm a compatible engine.
Full OM656 Compatibility
Every OM656 application verified by chassis code and year range. Each row links to its unit page with registration-checker confirmation.
| Model | Chassis | Variants | Years | Config. | Unit page |
|---|
Confirm your exact specification with the registration checker above.
OM656 Engine Prices
Every application group priced individually — compare used and reconditioned options across the full range.
| Application | Used from | Reconditioned from |
|---|
*Prices shown are current lowest listed prices and update as stock changes. The price on each listing is the price you pay — no hidden fees at checkout.*
What You Get with a OM656 Engine
What You Get with a OM656 Engine
What's included
Not included
Used or reconditioned?
Used OM656 units suit standard 350d replacements where the growing donor parc offers good value. Reconditioned units are recommended for 400d twin-turbo applications and premium hosts (S-Class, G-Class) where the vehicle value justifies the investment and a renewed timing chain assembly provides longer-term security. The OM656 3.0-litre inline-six diesel powers Mercedes-Benz's current premium range, from the E-Class through to the G-Class. As these vehicles accumulate mileage, replacement demand is driven by timing chain wear — the chain assembly is located at the gearbox end of the engine, making in-vehicle repair costly and labour-intensive — and turbocharger degradation on higher-mileage examples, particularly the twin-turbo 400d variants. A prepared OM656 unit addresses these wear points as standard, providing a complete replacement without the cost and downtime of an in-situ repair.
OM656 Engine Buying FAQs
Answers to common fitment, condition, warranty and delivery questions.
A:The OM656 is fitted to the Mercedes-Benz E-Class W213 (E350d, E400d), CLS C257 (350d, 400d), S-Class W222 and W223 (S350d, S400d), GLE W167 and GLS X167 (350d, 400d), and G-Class W463 (G350d, G400d). All applications are longitudinal. This engine is not fitted to any other brand.
A:OM656 is the primary engine code. The 350d and 400d badges refer to output levels within the same physical engine: 350d is the single-turbo variant (286 PS); 400d is the twin-turbo variant (340 PS). The BRF alias "D300/D350-era" refers to the Mercedes internal diesel designation generation. Note: the "300d" badge in most Mercedes models refers to the OM654 four-cylinder engine, not the OM656.
A:Used OM656 units suit standard 350d replacements where the growing donor parc offers good value. Reconditioned units are recommended for 400d twin-turbo applications and premium hosts (S-Class, G-Class) where the vehicle value justifies the investment and a renewed timing chain assembly provides longer-term security.
A:Use the registration checker on this page, cross-reference against the V5C logbook, and verify the engine code stamp on the block reads OM656. Confirm whether the vehicle is a 350d (single turbo) or 400d (twin turbo) to match the correct specification. For S-Class, confirm whether the vehicle is a pre-facelift W222 (which may have the earlier OM642 V6) or the OM656-equipped variant.
A:All OM656 units carry a 6–12 month warranty depending on condition (used or reconditioned). UK nationwide palletised delivery is available. A free compatibility check is offered before purchase to confirm the unit matches the buyer's chassis code and variant.
Find Your OM656 Engine
Enter your registration or select your vehicle below to confirm fitment and see available units at the listed price.