For an E320 CDI with the OM648 straight-six, identify the engine and DPF equipment before choosing a service kit. This earlier W211/S211 has different oil and air-filter references from the later V6, and its air-filter selection includes a chassis-number split. Use the service display together with the dated maintenance record.
Coverage: E320 CDI W211 saloon and S211 estate with the 3,222 cc OM648.961 straight-six, catalogued at 150 kW / 204 hp. MANN lists November 2002 to June 2005 as its application range, not UK registration cut-offs. The OM642 V6, petrol E320, W210 and other OM648 installations are outside this guide.
First separate the 3.2 straight-six from the 3.0 V6
| Check | This guide | Later E320 CDI guide |
|---|---|---|
| Engine | OM648.961 straight-six | OM642.920 V6 |
| Displacement | 3,222 cc | 2,987 cc |
| Catalogue output | 150 kW / 204 hp | 165 kW / 224 hp |
| Oil filter | MANN HU 721/2 x | MANN HU 821 x |
A 2005 registration does not reliably choose between these applications. Confirm the actual engine from the vehicle information before ordering. If yours is the later car, use our E320 CDI OM642 V6 maintenance guide.
The inspected Mercedes manual separately identifies the earlier E320 CDI as a 3,222 cc six-cylinder diesel at 150 kW. MANN supplies the exact engine-code match. W211 and S211 describe the saloon and estate; the covered engine-filter application includes both.
What ASSYST PLUS tells you on the earlier car
The 2004 manual uses service letters A–H to indicate workshop duration. A letter alone does not establish a fixed list of replacement parts. Record the complete display and mileage, then compare the required work with the service history.
The same chapter distinguishes the maintenance reminder from the oil-level display. An upcoming service does not tell you how much oil to add. Our ASSYST overview provides wider context without replacing the instructions for this build.
Verified details that change a service purchase
| Item | Decision for this OM648 application |
|---|---|
| Engine oil | The inspected manual separates non-DPF 229.3/229.5 from Euro 4 DPF 229.31. |
| Oil quantity | Its engine-with-filter table gives a 7.3-litre replacement reference. |
| Engine air filter | Check the A 196439 / A 196440 chassis boundary before choosing the reference. |
| Cabin filters | Match right-hand drive and the actual climate-control arrangement. |
| Diesel fuel filter | Resolve the optional water-sensor connection before buying. |
| Brake fluid | The manual specifies renewal every two years; retain the dated record. |
These checks do not mean every listed item must be replaced at every service. Filter application, scheduled renewal and condition-based work are separate decisions. A complete kit can contain suitable parts without proving they are all due now.
Build a useful record when history is incomplete
Start with invoices showing full part references, oil product and approval, date and mileage. Separate recorded renewals from entries that only say “checked”. Ask the workshop to identify gaps and explain which work is due under the applicable schedule, rather than assuming an old service stamp covers every consumable.
Retain gearbox-maintenance evidence separately from engine servicing. Confirm the actual gearbox and applicable service information before accepting a fluid or interval recommendation. This article does not turn a transmission-filter catalogue entry into a complete gearbox service specification.
Compare like-for-like quotations
Request labour and VAT, exact oil specification, and the parts included. Cabin-filter work should name the relevant arrangement; an engine-air-filter charge should match the chassis branch. If supplying parts yourself, agree this with the workshop before buying.
For product selection, the OM648 oil guide explains the 7.3-litre manual reference and separate DPF/non-DPF buying options. The straight-six filter guide sets out the air-filter boundary and cabin and fuel-filter conditions.
Stored cars and separate faults
Mercedes says battery-disconnected periods are not counted by the reminder. Keep that time with the maintenance record so calendar requirements are assessed correctly. Reset the reminder after the required work; retain the invoice rather than relying on a new countdown.
Report starting problems, warning messages or reduced power separately when booking. A routine service is not a diagnosis, and buying a filter does not establish that it caused a fault.
Browse the Mercedes maintenance hub and Mercedes diagnostic scanner guides. For a tool purchase, confirm the exact diesel engine, controller and required function.
Sources
- Mercedes March 2004 manual, printed pages 295–296 / PDF pages 298–299: service reminder.
- Mercedes manual, printed page 426: earlier engine identity.
- Mercedes manual, printed pages 454–455 and 458: oil and brake-fluid references.
- MANN 2024–26 catalogue, printed page 215 / PDF page 271: exact engine and equipment branches.
Research checked 20 October 2026. The inspected Mercedes-origin saloon/estate manual is the March 2004 German edition, preserved by a community archive. It supports the stated references, not a complete UK schedule for every build. The manual, Service Booklet and supplements supplied with your vehicle take precedence.
