GrizzlyMan

2012 Lexus is350, 86k miles
Crank the car this morning and this noise is coming out of the engine bay. IMO, it must be the water pump, everything else looks fine, belt, etc. And to me pulley noise is more of a bearing humming raspy noise just like when skate or wheel bearings are going out.

Zmon

iTrader: (2)

Sounds like the water pump to me. If you really want to confirm, touch a long screwdriver to the water pump and put your ear by the handle. Part number is 16100-39436 if you want an OEM pump, otherwise, the same exact part is available by Aisin without the Lexus stamp and I believe that part number is WPT-137. I would change your serperntine belt at the same time.

Mitho1991

it doesn't sound like WP to me.

GrizzlyMan

It turn out to be after all, the water pump.

The vehicle never overheated, nor leaked any coolant, it was that loud noise, and after taking the defective pump out, no signs of excessive play. It had only so slightly and using force, just a little play, barely noticeable. When spinning the base where the pulley goes, was very easy to move, not like when bearings are new has that heavy feeling in its rotation.






I know it did not look like it was the WP with such a horrid sound. I was so worried I just replaced it to see if it was that after all, than the repair itself.

​​​​The noise was at the center of the engine bay, and I could tell it was not from the pulleys.

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2013FSport

iTrader: (2)

A good test to isolate driven devices is to spray glass cleaner like Windex in stream mode at the belt and listen for sound change. A bad wp will keep making noise while a slipping / chirping belt will go silent.

Glad you got it resolved.