SLK250 CDI / SLK250 d servicing starts with the diesel engine oil and filter, the inspections due, and a check of air, cabin and fuel-filter history. Budget for the work your car needs, including time-based items and any separate gearbox maintenance, rather than buying a generic “SLK250 service kit”.
Coverage: SLK250 CDI / SLK250 d R172.403, OM651.980 diesel, 2,143 cc, 150 kW / 204 hp. MANN groups these badges in its October 2011–March 2016 catalogue application. Catalogue dates are not registration cut-offs. Petrol SLK250 and later SLC250 d are separate applications.
What should an SLK250 diesel service cover?
| Item | What to put on the job list |
|---|---|
| Engine oil and oil filter | Use the diesel approval and correct filter. The inspected Mercedes SLK250 CDI table gives 6.5 litres including the filter. |
| Engine air filter | Check the replacement record. MANN lists C 35 005 for the covered diesel application. |
| Cabin filter | Check which package includes it. MANN lists activated-carbon CUK 3621. |
| Fuel filter | Check when it was renewed and identify the heating configuration before ordering. |
| Brake fluid | Check the dated renewal record; Haynes lists a 24-month operation for its OM651.980 entry. |
| Condition checks | Include tyres, brakes, leaks, hoses, steering, suspension, lights and washers as applicable to the service. |
| Transmission | Ask for the gearbox type, previous maintenance and any additional work to be quoted separately. |
This is a planning checklist, not a demand to replace every filter at each visit. A car with recent engine-oil receipts can still have gaps in its fuel-filter, brake-fluid or transmission history.
Service A, Service B and extra work
The Mercedes manual calls A a minor service and B a major service. In some countries, an additional character identifies extra maintenance. Give the garage the complete display and ask for an itemised quote: a suffix is not a universal replacement-parts list.
Our Service A guide and Service B guide explain the wider labels. For the actual operations and intervals, Mercedes refers to the separate Service Booklet.
UK service costs: advertised examples
These prices were checked on 23 October 2026. They are advertised examples, not quotations obtained for your car.
| Provider and scope | Service A | Service B |
|---|---|---|
| MB&B, Cheltenham: SLK/SLC group, VAT included | From £200 | From £310 |
| DVB Automotive, Kent: named SLK250 CDI group, calculated including 20% VAT | £267.60 | £490.80 |
DVB lists £223 and £409 excluding VAT, so the displayed totals above are those figures multiplied by 1.20. Its page says the underlying price list was updated in March 2025: reconfirm it when booking. MB&B says age, mileage and condition may add parts or labour.
Ask each garage to separate the basic service, scheduled additions, repairs and VAT. Also ask whether it can update the appropriate Mercedes service record and provide a printed or electronic copy. This makes a cheaper base price and a more inclusive quote easier to compare.
Which intervals are useful starting points?
Haynes’ published SLK250 CDI OM651.980 plan lists brake-fluid renewal at 24 months and the engine air filter at 75,000 km or 48 months. These are attributed technical-publisher references; confirm the operations due against the car’s service information and history. The catalogue part number does not establish a replacement interval.
The Mercedes handbook says short-distance use, frequent city stops and prolonged idling can require more frequent work, including oil and air-filter changes. Tell the workshop how the car is used instead of judging the next visit only by its low annual mileage.
Buying oil and filters
Our SLK250 diesel oil guide covers the 6.5-litre reference, Mercedes approvals and a named buying option. The SLK250 diesel filter guide gives the air, oil and cabin references and the fuel-filter configuration check.
If supplying your own parts, agree this with the garage first. Confirm what the quote already includes, who will resolve any mismatch and how the fitted references and oil approval will appear on the invoice.
Storage and service records
Mercedes states that ASSYST PLUS does not count periods with the battery disconnected. Record the due date before storage and tell the workshop about disconnected periods. After work, keep the invoice, date, mileage, oil specification and completed operations; reset the reminder after the required service has been carried out.
Explore our Mercedes servicing and maintenance hub for other models. For fault investigation and tool selection, see our Mercedes diagnostic scanner guides.
Sources
- Mercedes handbook, printed pages 285–286 — ASSYST PLUS, additional work, storage time and arduous use; printed page 347 — diesel oil.
- Haynes SLK maintenance plans — named 250 CDI OM651.980 entry.
- DVB advertised prices and MB&B price guide — UK examples and VAT.
- MANN C 35 005 and CUK 3621 — named diesel applications.
Checked 23 October 2026. The Mercedes-hosted English manual is edition ÄJ 2014-2a, part 172 584 77 00; its named diesel row says SLK250 CDI. Use the handbook and service information supplied for your car, particularly for later SLK250 d specification differences. Contact Unusual Cars with corrections; keep vehicle-identifying details private.
