What is under this cover and why is it making this nasty noise?

[aelix]

Hi all

I have an 04 Mazda3s (2.3L) with about 110k miles on it. When I start it for the first time on any given day there's a loud buzzing noise from under the engine somewhere. The noise occurs regardless of weather/temps BUT it goes away after 2-3 minutes and doesn't come back until the engine has been off for a good few hours.

I have recorded a video of where I believe the noise is coming from... location of this cover is near the front left wheel. Can someone tell me (a) what's under the cover and (b) why it might be making such a nasty noise on startup? You'll notice that at the 20 second mark in the video the noise just goes away completely.

https://www.youtube.com/watch?v=cR1DhpgO9SE

[MAZDArati]

could it be a pulley or maybe even the power steering pump going? thats my thoughts.

[Flagrum_3]

Sounds like possibly the power steering pump. The noise is quite similar to the PS pumps on our buses when started cold and due to shitty fluid. Check your PS fluid level or replace it, see if that helps.


_3

[geobur]

oh god that sounds awful. Hopefully it isn't anything too major. Sounds like a lawnmower.

[CarLadyLisa]

Take it to the mechanic. Sounds sick and not in a good way.

[morganc]

That cover is the transmission fluid pan. Could be a bad torque converter or input shaft bearing. Any slipping/driveability issues?

[morganc]

Could be low tranny fluid, too. It sounds hydraulic as opposed to mechanical. Once the tranny fluid heats up enough, the main pump of the tranny primes and the noise goes away until the fluid cools down.