Splash pan not tightened?

Had a popping noise going on and mentioned it to the service guy at my 15K service.
When they buzzed me to let me know my truck was ready they told me the popping noise was the splash pan.
What is the splash pan and is it removed for a oil change? Service guy was clueless.

 

The front skid plate does have to come off for an oil change. Bad design. But I thought that the Pro has a skid plate where there is a small panel that can be removed to access the filter.

 

Theres a access panel in the TRD skid plate.

 

A popping noise makes me think it's something in the suspension. My tacoma made a popping noise and it was the lower control arm / alignment cam bolts that were loose. I would think a skid plate would be more of a rattle

 

I'm assuming the splash pan is aka skid plate. Idk what else it would be. I'm sure someone will be much more help than I.

 

The popping noise was probably coming from the skid plate there is a TSB about that noise. Had one in the shop a couple weeks back that another tech worked on and I believe he installed insulator washers, but don't quote me on that.

 

Thanks is their a number for the TSB?

The popping noise is back, I was there 3 hours for a oil change and this issue and the noise was back a few days later.
My local dealer is starting to lack in the service department.