L-shaped 3-foot long plastic attached to the bottom of the front bumper skin

[pomidor]

...what is its purpose ... besides telling you that you've parked over a curb to far and you're about to skin something important if you go any further?

I took mine off. It looked, as all of them look, like it was designed to be an air-brake. I'm sure that's not its purpose, but the air-brake-like shape bothered me so off it went.

Few days later, front-left bearing became noisy.

Was that plastic thing (what the hell do you call it anyway?) designed to channel air into the wheels? Cooling brakes, or bearings, perhaps? Or was my bearing failure just a coincidence (car has ~160 k km on it)?

 

[haveahotcarl]

Many of the plastic pieces under the car are designed to direct/deflect air in some way (Google "air dam" or "diffuser"). Usually they help direct air under the car and allow air to flow through the engine compartment properly. Some do have "scoops" that direct air to certain components to help with cooling as well.

As for the piece you removed, a picture would help determine if that was actually the cause.

But, my vote is for coincidence. Bearings don't need the type of cooling an air duct would provide.

 

[pomidor]

... As for the piece you removed, a picture would help determine if that was actually the cause.
... Bearings don't need the type of cooling an air duct would provide.

So if the bearing wouldn't need such cooling, could it than be meant to cool the brakes? I'd like to take it off (again), but I don't want my actions to cause any undesired effects

Here are some pictures of its location and shape:

 

[Silverspeed2015]

that wasn't on my car when i bought it, but im glad it doesn't look very good under there

 

[dmention7]

Many of the plastic pieces under the car are designed to direct/deflect air in some way (Google "air dam" or "diffuser"). Usually they help direct air under the car and allow air to flow through the engine compartment properly.

^^ This

It's hard to comment on the specific function, but it's generally there to help improve airflow either through the engine bay (to help pull air across the radiator at speed by generating lower pressure below the engine bay) or across the underside of the car for aerodynamics. Not going to have a lick of an effect on anything to do with brakes or wheel bearings.

 

[haveahotcarl]

So if the bearing wouldn't need such cooling, could it than be meant to cool the brakes? I'd like to take it off (again), but I don't want my actions to cause any undesired effects

Here are some pictures of its location and shape:

That's what I figured you were talking about. It does help airflow through the engine bay like dmention7 said. You could take it off and maybe you won't notice many/any differences... but I wouldn't.

 

[pomidor]

Alright. I'll leave it on.

 

[FunkyBuddha]

It prevents s*** from coming up into the engine bay too. I tore mine open and there was a lot of dust/dirt that would come up. My power steering belt would be really dirty. Protects from water spray from rain etc.

 

[SCMP3]

I took mine off because of being low.....no difference

 

[thecrash91]

i always thought it was a warning your about to bottom out kinda deal. cuz it has saved me from many a curb (not really, just wanted to say that)

 

[hornsfan10609]

Damn my car doesn't even have one, I never knew it was missing.

 

[haveahotcarl]

It prevents s*** from coming up into the engine bay too. I tore mine open and there was a lot of dust/dirt that would come up. My power steering belt would be really dirty. Protects from water spray from rain etc.

The dirt in the engine bay was likely a side effect of stagnant air in the engine bay.

 

[FunkyBuddha]

The dirt in the engine bay was likely a side effect of stagnant air in the engine bay.

No trust me...it was from water spraying up when it's raining outside. Snow would come up as well. I had a rock bounce up, and lodged itself in my power steering belt as well causing it to misalign and shift a couple of grooves over.