Holden Commodore: VF 3.6L LFX Timing Cover Cam Seal Seep

The LFX and LWR 3.6L V6 engines fitted to VF Commodores have a plastic composite front timing cover that seals the front of both cylinder heads via a multi-piece gasket set. The camshaft position sensor O-rings and the cam phaser seal at the front of each cam shaft are a known failure point. Thermal cycling causes the plastic cover to micro-flex, fatiguing the cam seal lip and the front cover gasket bead. Oil wicks from the cam seal area, tracking down the front of the engine and accumulating on the front subframe or dripping onto the harmonic balancer. The leak is often confused with a valve cover gasket leak but originates higher at the cam nose. At high mileage the VVT phaser seal also fails, mixing oil into the cam phaser port and causing VVT rattle codes alongside the external leak. Front cover removal requires significant labour including timing chain disassembly.

• Oil seeping from the front of the engine, tracking down the harmonic balancer or front subframe
• Burning oil smell from the engine bay as oil contacts the exhaust manifold
• Oil staining or residue at the top front of the engine near the cam cover and timing cover join
• Check Engine Light with cam position sensor fault codes (P0341, P0346) if the oil has contaminated the cam sensor
• VVT rattle or cam phaser noise at startup if the phaser seal has also failed

With the engine at operating temperature and then allowed to cool for 20 minutes, inspect the front of the engine with a torch — trace any oil film upward to its source. Oil at the very top front of the engine near where the timing cover meets the cylinder head indicates a cam seal or front cover gasket leak rather than a valve cover gasket. Shine a UV torch on the front subframe and radiator support to identify oil paths. Scan for cam sensor fault codes. Check whether the cam cover gasket area is also leaking to distinguish between the two common leak points.

Parts involved: Cylinder head, Timing chain, Rocker / valve cover.

$900 to $2,800 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 any oil leak from the front of the engine been investigated or repaired?”
• “Has the front timing cover or cam seals ever been replaced?”
• “Have any cam position or VVT-related fault codes been logged?”
• “Has an oil consumption issue been noted between services?”

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.