I have an 02 TL and while looking at my tranny, I spotted under the front motor mount a 3/8 rubber tubing that looks like it snakes towards the engine on top of the chassis. Does anyone have an idea what it is? In my car, it appears that it broke into pieces off long ago from being brittle.

 

Not sure if your generation TL uses a vacuum line for the mount.

 

Yup the oem mounts are vacuum controlled for OPs car. That could be the vacuum line but if it were rotted off I think you'd end up running quite crappily due to the leak. Are you having any rough idle issues or anything like that??

 

a failed mount will cause mystery vac leak, so a missing vac line...

ck the front mount,,a small nipple there with no line attached?
compare to rear mount- its the same type
both are fluid filled and vac boosted under acceleration to stiffen system

 

I had the engine mounts replaced months ago. They probably thought I never bother to ever see it. Could this be a DIY for a novice?

 

Yep. just get some new vacuum tube or order teh correct one here

http://www.acuraautomotiveparts.org/...catdisplay.jsp

 

its possible they installed aftermarket mounts without vac boost
Some parts place offering mount for 30 bucks instead of 150,,well lets use that!
they dont know why so much price diff....
then left line hanging there, having no clue what it does

which came first, the wrong mount or the hanging line!

you can use those cheap mounts if you plug the vac line
look at the top end of it for plug

parts price will tell you a lot
the OE front mount is ~150$
pass side 50 (normal solid rubber mount)
rear OE 150