Reference specification for the 3.0‑litre V6 diesel engine (OM642), fitted across C‑Class, E‑Class, ML/GLE, GL/GLS, Sprinter, and other Mercedes models. No opinions, no verdicts — just the numbers, correctly sourced and verified against variant differences.
The OM642 takes approximately 8.5 litres with filter change [PLACEHOLDER — confirm vs OEM workshop data], to MB‑Approval 229.51 specification, typically 5W‑30 or 5W‑40.
Full specification table, variant differences, common mistakes, and the oil cooler seal caveat explained below.
| Spec | Value |
|---|---|
| Capacity with filter change | ~8.5 litres [PLACEHOLDER] |
| Capacity without filter change | ~8.0 litres [PLACEHOLDER] |
| Viscosity grade | 5W‑30 or 5W‑40 (low SAPS) |
| MB specification | MB‑Approval 229.51 [PLACEHOLDER — confirm exact spec number] |
| Change interval | 12 months / 15,500 mi [PLACEHOLDER] |
| Oil filter type | Cartridge, front‑mounted (V6 layout) |
Figures marked [PLACEHOLDER] require confirmation against the OEM workshop manual before this page goes live — flagged here deliberately rather than guessed.
The OM642 is fitted across a wide range of models, and while the core specification is consistent, sump capacity and oil cooler design vary slightly by application and model year.
| Application | Capacity Note | Filter Access |
|---|---|---|
| C‑Class W204 (2007–2014) | Standard 8.5L figure applies | Front‑mounted, accessible from above |
| C‑Class W205 (2014–2021) | Standard figure, some early builds noted slightly different sump capacity | Front‑mounted |
| E‑Class W211 (2005–2009) | Standard figure applies | Front‑mounted |
| E‑Class W212 (2009–2016) | Standard figure applies | Front‑mounted |
| E‑Class W213 (2016–2023) | Standard figure applies | Front‑mounted |
| GLE W166 (2015–2019) | Standard figure, some variants with additional oil cooler | Front‑mounted, tighter access |
| GLS X166 (2012–2019) | Standard figure applies | Front‑mounted |
| Sprinter W906 (2006–2018) | Standard figure, but some commercial variants have larger sumps | Front‑mounted, accessible from below |
The manufacturer's 15,500‑mile interval assumes motorway‑weighted use. However, the OM642 is known for oil cooler seal leaks — the O‑ring seal between the oil cooler and the engine block (positioned in the V of the engine) can fail, leading to oil leaks that contaminate the engine bay and, if left unchecked, can cause oil starvation and engine damage [PATTERN DATA]. This is a labour‑intensive repair, typically costing £800–£1,500 at a specialist, because the intake manifold and other components must be removed to access the cooler.
Independent specialists we've spoken to frequently recommend a shorter, 10,000‑mile interval for OM642‑powered cars, especially for those used in urban driving or with high mileage. This isn't manufacturer guidance — it's a practical adjustment specialists make based on what they see coming through the workshop, and it costs a fraction of the alternative, which is an engine rebuild or replacement due to oil starvation from a failed seal. We cover this in detail on our OM642 Oil Cooler Seal Failure page.
The dipstick and filler cap on the OM642 are both clearly marked and accessible from above. The oil filter is front‑mounted and can be accessed after removing the engine cover. Confirm your exact build spec via the engine number stamp described on our Engine Number Location guide before assuming these figures apply — early and late production runs occasionally carry minor running changes that aren't always reflected in aftermarket reference sources.
Getting oil spec wrong on an OM642 isn't a minor issue. The MB‑Approval 229.51 specification exists specifically to provide the low‑SAPS formulation required to protect the diesel particulate filter, as well as the high‑temperature shear stability needed for the V6 design. Using a standard, non‑approved oil introduces deposits that accumulate in the oil cooler seal area, accelerating seal failure, and can also clog the DPF over time. The viscosity grade matters similarly: 5W‑30 or 5W‑40 is specified for cold‑weather flow characteristics that directly affect how quickly oil reaches the bearings on a cold UK morning, which connects directly to the failure patterns described on our OM642 oil cooler seal page. This is also why we treat "any 5W‑30 will do" as a genuine misconception worth correcting rather than a pedantic technicality — the MB‑Approval matters as much as the viscosity number, and cheaper oils meeting the viscosity spec without the approval are a false economy that shows up as a much larger bill years later.
Every Figure SourcedUnverified numbers flagged, never guessed.
Last Verified February 2026Reviewed on a regular schedule, not left to go stale.
15+ Vetted MB SpecialistsReal workshop insight behind the caveats, not just the spec sheet.
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