Here's an old ChrisFix video that might help you pinpoint the specific issue.
If the water pump itself is going bad I would replace it, the pulley and the old water pump gasket with new parts for peace of mind.
The iQ's repair manual can be accessed on Toyota's techinfo site for $25 for a two day subscription. This will provide fastener torque values, steps, required tools etc.
If the water pump itself is going bad I would replace it, the pulley and the old water pump gasket with new parts for peace of mind.
The iQ's repair manual can be accessed on Toyota's techinfo site for $25 for a two day subscription. This will provide fastener torque values, steps, required tools etc.