Is the factory standard TL airbox (2004-2006 for example) a cold air inlet style? Someone told me the airbox lets in under-hood air at some point in its path. That seems rather dumb if accurate. Anyone know for sure? Thanks.

 

The factory setup is a bit of a compromise. Air is pulled from in front of the battery. Also, there's a cold air tube that feeds air into the front of the battery from the lower front bumper. Problem is, the two aren't connected, so hot engine air is mixed with air that comes from the bumper.

I guess the designers had to make it idiot proof for those who like driving into standing water.


See first diagram in this thread

 

Thanks Andrew. Man, that stock airbox assembly is complicated by looking at the attached photos. Cars have had a form of cold air intake for years now and I don't recall all the convoluted pathways on other vehicles. For water to climb all the way up the tube to the filter inlet would seem highly unlikely. If you went through a large puddle it probably wouldn't be at full throttle where there would be the force to get water through the filter. When the weather clears I might take a look at what I can do to simplify the routing or if there are openings under the hood allowing hot air in sealing them off if possible. I'm a tinkerer by nature but don't want to do any major surgery or have any nasty noises.