I have a 2002 Highlander Limited, 39K miles. over past several months has been sporadically making grinding noise when accelerating from a stop or red light, not immediately upon depressing the gas but a second later (2-5 mph). It makes noise regardless of a hard or soft on the gas pedal. Recently it has occurred more, particularly going up hill. The noise only occurs on acceleration from a stop, once the car moves more than 5 mph, then everything is fine. when I drive on local/highway, I do not experience this noise (once vehicle in motion, it does not experience noise, only when stop and go). The sound seems to be coming from anywhere below the driver to second row seat, and not from engine area. any insights to this is greatly appreciated.

I'm having the same problem. 2002 Highlander Limited w/68K miles. Because it's sporadic, mechanic cannot isolate problem. I would welcome any input/findings posted here.

(IMG:style_emoticons/default/nahrung034.gif) I have a 2005 Toyota Highlander V-6 front wheel drive w/ approx 42k miles.
For the past 2 years there has been a slight grinding noise during acceleration that last only
a few seconds. Lately it has been getting louder. The Toyota dealer says bring it in for a
check up (65.00) but offered no help by phone. It took me about a hour to finally figure out
what was causing the noise after checking under the car, under the dash etc. It's the air
box with the air filter. It's a big black box that moves when torque is applied to the engine
thus creating a grinding noise because it's loose. It could have been from other service work
done but I wedged it around a bit and got it centered and no more noise....hope this helps.

Mike in Tampa

Would love to know if the "black box" was the cause of everyone else's problem. I am having the same problem with my 2002 Highlander (with 60,000 miles) and actually found your website searching the internet for some clues. The car has been making the noise off and on for a couple of months. I had my car in for service and mentioned the problem to the dealer, of course the car did not make the noise while it was there -- so there was no diagnosis. Keep posting!