Hi, new to forum. I have a mazda5. I was looking for oil leak this morning and notice a a hole under my engine(driver side).. Not exactly sure what that was. Feel urgent. so, I post it here to get your opinion. Thank you for your input!

 

Yes its " a hole " , not anything to be concerned about.

 

Hi, glad to hear that. But, why nothing to be concerned about? I saw a big gear inside it. Should I grease it? Thank you.

 

Its the ring gear, its what the starter motor engages to start the engine. No need for grease.

 

If this is the case, I will do nothing.

 

I wonder if that's some kind of inspection port that's supposed to have a rubber cover or something.