Nissan Murano: VQ35DE Engine Oil Sludge from Extended Service Intervals

The VQ35DE 3.5-litre V6 is susceptible to accelerated oil sludge formation when oil change intervals are extended beyond manufacturer recommendations or when the incorrect viscosity is used. Sludge accumulates in the oil galleries, VVT solenoid passages, and around the oil control rings, progressively restricting hydraulic pressure to the variable valve timing phasers and upper valvetrain. Blocked VVT oil passages trigger camshaft timing fault codes (P0011, P0021, P0024) and eventual camshaft phaser seizure. Severely sludged engines can suffer main bearing starvation and rod bearing failure. The oil gallery gaskets behind the rear timing cover are a known weak point that can exacerbate low-pressure conditions.

• Check engine light with camshaft timing codes P0011, P0021, or P0024 stored
• Rattling or ticking from the valve covers on cold start that takes longer than 10 seconds to clear
• Thick, dark sludge visible inside the oil filler cap or on the dipstick
• Noticeable loss of power or rough idle due to incorrect valve timing from blocked phaser passages

1. 1

   Clean oil appears amber and translucent; sludge appears as a thick, dark, tar-like deposit.

2. 2

   Pull the dipstick and check for a thick, dark, mayonnaise-consistency oil that does not flow freely.

3. 3

   Ask the seller for service records confirming oil changes at or below 7,500 km intervals.

4. 4

   With the engine running, scan for stored or pending codes P0011, P0021, or P0024, which indicate VVT passage restriction.

5. 5

   Listen for a rattling noise from the top of the engine on cold start, which indicates phaser starvation.

6. 6

   Remove the oil filler cap and use a torch to inspect the underside of the cam cover for sludge.

$900 to $6,500 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.

• “Can you show me service records for every oil change?”
• “What oil brand and viscosity was used and at what intervals?”
• “Has the engine ever thrown any check engine lights related to camshaft timing?”
• “Has the engine ever been flushed or the oil gallery gaskets replaced?”

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.