Plan CLK280 / CLK350 servicing around an 8.0-litre engine-oil change with filter, the inspections due, and the history of air filters, cabin filters, six spark plugs and brake fluid. The two M272 V6 models can share a maintenance guide, while cabin-filter selection needs a separate check of steering side and climate-control equipment.
Coverage: CLK280 C209 coupé / A209 cabriolet with M272.940 3.0-litre V6, and CLK350 with M272.960 3.5-litre V6. Mercedes lists 170 kW / 231 hp and 200 kW / 272 hp respectively. These are petrol models; the older M112 CLK320 and OM642 CLK320 CDI have separate guides.
What should the service include?
| Item | What to check or request |
|---|---|
| Engine oil and filter | The inspected Mercedes table gives 8.0 litres including the filter for both models. Select the correct oil approval and record the product. |
| Engine air filtration | MANN lists C 3698/3-2 for the CLK280 and CLK350 M272 applications. |
| Cabin ventilation filters | Identify THERMATIC or THERMOTRONIC and right- or left-hand drive before ordering. |
| Spark plugs | NGK UK lists six PLKR7A plugs, stock 4288, for each covered engine. |
| Brake fluid | Check the dated renewal record. The inspected Mercedes handbook specifies every two years. |
| Coolant | Check its history: the handbook specifies renewal by 15 years or 250,000 km at the latest. |
| Condition and transmission | Ask for inspection findings and a separate assessment of gearbox maintenance history. |
Use this list to identify work due now. It does not mean replacing every filter, plug and fluid at every service. Check invoices as well as the dashboard reminder, particularly where the car has changed owners.
Service A and B: compare the actual work
The inspected CLK handbook describes A as the smaller maintenance visit and B as the larger one. It shows time- or distance-based due messages. Give the garage the complete display, mileage and service history when asking for a quote.
Our Service A guide and Service B guide explain the wider terminology. An advertised A/B package still needs to be matched to the car’s operations and additional work.
UK service costs: two advertised examples
Checked on 24 October 2026, these prices provide a starting point for comparing quotations:
| Provider and advertised scope | Service A | Service B |
|---|---|---|
| Power Developments, Essex: CLK petrol 2.5–3.6 litres, labour/parts/VAT included | £179 | £299 |
| MB&B, Cheltenham: CLK group, VAT included | From £200 | From £310 |
Power Developments lists spark-plug servicing as a separate enquiry. MB&B says age, mileage and condition may require additional parts or labour. These are advertised group prices, not quotes obtained for an individual CLK280 or CLK350.
Request separate lines for the basic service, plugs or filters due, brake-fluid work, gearbox work and repairs. Confirm VAT, consumables, the parts used and the service-record entry. Package names alone do not show whether two garages are quoting for the same visit.
Six spark plugs, not the older CLK320’s twelve
NGK’s UK catalogue lists six PLKR7A plugs for M272.940 and M272.960. This is a useful quote check: the older M112 CLK320 has a different ignition application with twelve plugs. Ask when the correct plugs were last renewed and whether their replacement is included in the quotation.
For the parts themselves, see the CLK280 / CLK350 filter and spark-plug guide. It separates engine filtration from the UK cabin-filter choices.
Buying oil and parts for the visit
The CLK280 / CLK350 engine-oil guide explains the 8.0-litre reference, handbook approvals and a named oil buying option. If supplying parts to a workshop, agree that beforehand and check what its package already includes.
Keep the full oil name, approval, filter references, plug reference, date and mileage with the invoice. A receipt saying only “service kit” is less useful when checking what has already been replaced.
Older-car history and seasonal storage
At this age, look for evidence of coolant renewal rather than assuming an original “lifetime” fill never needs attention. Have the garage check the correct fluid and the actual work required; a top-up and complete renewal are different records.
The CLK handbook also says ASSYST does not count time with the battery disconnected. Note the due date before storage and tell the workshop about disconnected periods. Reset the reminder after the required maintenance is complete.
Explore the Mercedes maintenance hub and our Mercedes diagnostic scanner guides for other models and fault-investigation tools.
Sources
- Mercedes 2008 European handbook, printed pages 220–221 — ASSYST and stored time; printed pages 359–361 — oil quantity, coolant and brake fluid.
- NGK UK catalogue, printed page 46 / PDF 48 — both M272 engines, plug reference and quantity.
- Power Developments CLK prices and MB&B price guide — advertised UK examples and VAT.
- MANN engine-air application and RHD THERMATIC cabin application — named models.
Checked 24 October 2026. The 2008 European manual used here is a Mercedes-origin French document, edition ÄJ 2008/1 b, mirrored by Fichier-PDF; its introductory notice specifies German-market applicability. The Mercedes-hosted CLK350 manual is a North American edition. Figures are attributed to those editions; match the handbook and service information supplied for your car. Contact Unusual Cars with corrections.
