Red triangle & P1116

16290-21011 is the engine coolant heat recovery pump. You do not need to worry about that if noise is the only issue, since it only runs for a few seconds upon startup and shutdown.

A more important concern is why the engine coolant was low. You will need to watch the coolant level over the next few days. If it continues to drop, then there is a leak that must be fixed.

The most likely place for the leak is the engine coolant pump. Have you had a chance to look at the pump pulley and the air conditioner compressor housing, to see if there is any pinkish coolant residue?

 

It's the coolant pump near the right side inverter. Take less then 15 min to change your self. Turn car iff obviously 1. Unbolt black bracket next to right side inverter. 2. Put catch pan below the car under pump 3. Use tools to remove hose clamp and bolts that hold it. Take it out. And replace it. And put together in reverse order. Coolant pump is usual issues with it

 

I assume you are referring to the inverter coolant pump which is located behind the driver's side headlight, and in front of the main relay/fuse box near the inverter. This pump has nothing to do with the OP's problem since the OP has complained of low engine coolant.

 

That's good to hear. However you should keep checking the engine coolant in the radiator and the overflow container over the next few days when the engine is cold, to make sure that the coolant remains full. If not, then you will know you have a leak, whether or not you can find it.

Once you have decided that a leak exists, then if you can't find it, you should seek professional help. The most likely place for an engine coolant leak is at the engine coolant pump which will develop a leaky bearing. You may see dried coolant on the inside of the pulley or deposited upon the air conditioner compressor housing. This will appear as a pinkish stain.