I have a 2004 Toyota Tacoma. Recently in cold weather there is a high-pitched whine/squeal coming from the engine area. I have ruled out belts with belt dressing spray, and I think I've narrowed it down to the water (coolant?) pump because if I apply a small amount of WD40 on the shaft behind the pulley (is that the term for the wheel the belt turns?) it will stop squealing until the next commute.

My best guess is that the pump bearings are going and it should be replaced. If this is a correct diagnosis, should I replace the unit entirely or is there another fix (e.g. new bearings)? Since I don't know enough about working on engines, I will likely have a shop do the work. That said, should I address this immediately, or should I wait until the belt replacement is due (in another year perhaps) to save on labor costs?

1 Answer 1


Yes, I believe you have correctly diagnosed the problem. You should address this as soon as possible as the pump may seize up at any time. The squeal is your warning signal.

If it seizes then you'll lose coolant flow and also likely lose other things on the same drive belt like alternator, power steering, and A/C.

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    Also, just have the whole pump replaced as it would probably be more expensive in labor to tear it apart and replace the bearing. As far as when it should be done, as soon as possible as if it fails you'll be a lot worse off than simply paying a little extra for a new belt.
    – Techlord
    Commented Dec 10, 2019 at 4:53

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