Bearing Noise at front of motor, 04 LC

[Borrego]

Figured I would keep relevant noisy belt / pulley issues in this thread.

Trying to diagnose a slight chirp in my engine bay.

Mine was the fan pulley bearing.
Mine started with a cold morning chirp like you mentioned, but then turned into a bad bearing sound (gargling marbles) after about a month. Fan felt firm with the belt on, but with it off, it had about 1/8" of play. I couldn't reproduce the noise by hand, but figured since there was play in the fan, and it would spin and catch like you mentioned yours is doing, and every other pulley spun free and smooth, I would replace the fan pulley bracket. Fixed it.
A lot needs to comes off to get to it, but it's not hard.
If this ends up being your issue, I would definitely go with an OEM part for this. I've heard aftermarket bolt holes don't line up. Plus the original one lasted a long time. There are a lot of writeups on how to do it here on Mud. Best of luck!!

 

[Mike NXP]

Thanks for the heads up, is that driven by the timing belt? I suppose I could diagnose that by removing the serpentine belt and running motor. If the noise remains that could be a culrpit, but if it goes away then I am back to external parts.


Had toyota do my timing belt and inspect / replace parts in there, but to be fair that was 30-40k miles ago.

 

[Borrego]

No, it's driven by the serpentine. Toyota did my timing belt and water pump about 10k miles before this issue happened. Found out that a lot of folks have this changed out at the same time because you're more than 1/2 way torn apart for the timing belt. Like I mentioned, it's not too tough of a job. Just keep track of where everything goes.

 

[Mike NXP]

No, it's driven by the serpentine. Toyota did my timing belt and water pump about 10k miles before this issue happened. Found out that a lot of folks have this changed out at the same time because you're more than 1/2 way torn apart for the timing belt. Like I mentioned, it's not too tough of a job. Just keep track of where everything goes.

Gotcha, thanks. So I'm still trying to determine the best way to diagnose if it's bad. By spinning the pulley that the serp belt wraps around, wouldn't I be able to feel symptoms of a bad bearing? When I did my tensioner a few weeks ago everything felt smooth and didn't require any attention.

 

[Mike NXP]

When engine is at operating temp , and engine is off, I am able to spin the fan pretty freely. Spins for 4-5 rotation.

What is the proper operation of our fan clutch when cold / warm ?