Nissan Skyline: RB20 Water Pump Bearing Failure and Impeller Spin

The OEM water pump on R32 RB20 engines (both turbo and NA) is prone to bearing wear and plastic impeller spin-off on the shaft as the press-fit degrades with age. When the impeller spins freely on the shaft the pump produces flow but at significantly reduced pressure, causing overheating under load without obvious external leaks. Bearing failure presents as a growling noise and coolant leak from the weep hole. At 30+ years old, NZ/AU import water pumps are largely at or past end-of-life.

• Overheating under load but normal at idle
• Growling or rumbling from front of engine
• Coolant weeping from pump body weep hole
• Temperature gauge climbing on motorway runs

1. 1

   With the engine cold, check for play in the water pump pulley by gripping and rocking — any movement indicates bearing wear.

2. 2

   Inspect the pump body weep hole (small hole below the pulley shaft) for dried coolant residue or active weeping.

3. 3

   Review the temperature gauge behaviour under sustained highway load.

Parts involved: Water pump.

$400 to $900 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 water pump been replaced, and when?”
• “Has the car ever overheated or shown temperature spikes?”
• “When was the timing belt last changed and was the water pump done at the same time?”

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.