Final answer:
-Both. A defective water pump bearing can cause a growling noise when the engine is idling, and coolant leaking past the pump seal can ruin the bearing.
Step-by-step explanation:
A defective water pump bearing can indeed cause a growling noise when the engine is idling. The water pump bearing is responsible for supporting the rotating shaft of the water pump. If the bearing becomes damaged or worn out, it can produce a growling or grinding noise. This noise is typically heard when the engine is idling because the water pump is not under a heavy load at that time.
The second statement regarding coolant leaking past the pump seal is also correct. If coolant leaks past the pump seal, it can come into contact with the water pump bearing. Coolant is not meant to lubricate the bearing and can cause damage if it enters the bearing area. Over time, this can lead to the ruination of the water pump bearing.
Therefore, both statements are correct, and the answer is A-B-Both.