Mitsubishi ASX: MIVEC Timing Actuator (OCV) Cold-Start Rattle

The 4B10 1.8 and 4B12 2.0 MIVEC engines use an oil-pressure-operated variable valve timing actuator on the intake camshaft. At cold start, the oil control valve (OCV) does not receive adequate pressure for several seconds, allowing the actuator vanes to rattle against their housing stop pins. In high-mileage or poorly serviced engines, sludge accumulation in the OCV screen accelerates the lag. Prolonged neglect causes the vane actuator itself to stick in a retarded position, triggering a P0011 or P0014 DTC and causing rough idle, poor fuel economy, and reduced power across the rev range. OCV replacement is straightforward, but a stuck or scored actuator requires camshaft removal.

• Rapid metallic rattling from the front of the engine on cold start, ceasing within 10–30 seconds as oil pressure rises
• Stored P0011 or P0014 DTC with associated rough idle or hunting at warm operating temperature
• Fuel economy noticeably worse than specification (combined 7.5–8.5 L/100km for 4B12) with no other obvious cause
• Reduced power and flat mid-range response once actuator sticks in retarded position

1. 1

   Start the engine cold and listen for a metallic rattling from the front-top of the engine during the first 5–20 seconds.

2. 2

   Confirm the rattle stops once oil pressure builds.

3. 3

   Scan for DTCs P0011 (intake cam over-advanced) or P0014 (exhaust cam over-advanced).

4. 4

   Check engine oil condition and service history.

5. 5

   If a workshop inspection is possible: Remove and inspect the OCV filter screen for sludge blockage.

$180 to $1,400 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.

• “Does the engine make a rattling noise for the first few seconds when started cold?”
• “Has the engine oil been changed at or before 10,000 km intervals using the correct grade (5W-30 or 0W-20)?”
• “Has a DTC scanner ever shown a P0011 or camshaft position fault?”

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.