Mercedes-Benz C-Class: M274/M264 HPFP Cam Follower Wear on DI Variant

The M274 and M264 direct injection petrol engines use a mechanical high-pressure fuel pump (HPFP) driven by a dedicated lobe on the intake camshaft via a hardened roller cam follower. When the cam follower wears through its hardened surface coating, it begins to abrade the soft substrate and score the camshaft lobe. This reduces the pump's ability to generate sufficient injection pressure, causing fuel delivery issues. In advanced cases the cam follower can collapse entirely, destroying the camshaft lobe and requiring full camshaft replacement at significant cost. Extended oil service intervals, low oil level operation, or use of non-approved engine oil accelerates follower wear. The fault is well-documented across multiple Mercedes-Benz and partner-brand engines sharing this HPFP drive architecture.

• Extended cranking before engine starts, particularly when hot
• Rough running, hesitation, or misfires under load
• Reduced power output, especially above 3000 rpm
• Fuel pressure fault codes such as P0087 (fuel rail pressure too low) or P0191
• Engine ticking from the valve cover area related to cam follower collapse
• In severe cases, metal contamination visible in engine oil on dipstick

1. 1

   Request an OBD scan for fuel rail pressure fault codes.

2. 2

   Ask about any history of hard starts or fuel system work.

3. 3

   Check oil service history carefully; intervals beyond 12 months or 12,000 km significantly increase follower wear risk.

4. 4

   Confirm only MB 229.5 or 229.51 specification oil has been used, as non-approved low-SAPS oils accelerate wear.

5. 5

   If a workshop inspection is possible: The cam follower condition can be inspected after removing the HPFP from the valve cover without major disassembly.

Parts involved: High-pressure fuel pump.

$750 to $5,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the high-pressure fuel pump cam follower ever been inspected or replaced?”
• “Has the engine oil been changed strictly within MB-specified intervals?”
• “Has there ever been a hard start condition or fuel pressure warning?”
• “Have any fuel system fault codes been stored or repaired?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.