RG5384
05-20-2012, 11:12 AM
I'll try to make this as breif as possible. I'll state in advance any and all help/ideas are welcome and appreciated.
The vehicle is a 2004 highlander limited (http://www.toyotanation.com/forum/#) v-6 fwd.
The problem is a knocking(or rattling as my wife describes) noise, that happens when:
1. You accelerate moderately, it sounds absolutely horrific if you gun the car from a stop. (can happen only once, or will happen repetatively, especially in a tire slipping condition(I.E. rain, or just accelerating too quickly so that the tire spins)
2. You hold the brake pedal down firmly while in drive and tap the gas(happens one time only, but you can duplicate it indefinately)
Other things figured out:
1. The noise went away for about 4 months after I backed quickly up a hill. I tried that again-no dice.
2. The noise will change in pitch if you turn the wheel to the right and hold the brake and tap the gas.
3. If you prevent the engine from rocking using an extension/block of wood etc the noise does not happen.
4. All motor mounts are in good condition.
5. It does not happen if you press the gas while holding the brake in reverse.
6. No noise at all going over bumps/rough roads.
7. The noise seems to be dependent on the engine tilting backwards.
The problem started about a year ago, when I was working as an advisor at a large toyota dealer. I took it in at that time, and my head mechanic looked at it for about 3 hours, couldn't pinpoint it and basically said "we can throw parts (http://www.toyotanation.com/forum/#) at it if you want, but i'd just drive it to be honest". I'm no longer working as an advisor, and the problem has gotten substantially worse. I'm hoping someone else has had the same or similar problem.
Thanks!
The vehicle is a 2004 highlander limited (http://www.toyotanation.com/forum/#) v-6 fwd.
The problem is a knocking(or rattling as my wife describes) noise, that happens when:
1. You accelerate moderately, it sounds absolutely horrific if you gun the car from a stop. (can happen only once, or will happen repetatively, especially in a tire slipping condition(I.E. rain, or just accelerating too quickly so that the tire spins)
2. You hold the brake pedal down firmly while in drive and tap the gas(happens one time only, but you can duplicate it indefinately)
Other things figured out:
1. The noise went away for about 4 months after I backed quickly up a hill. I tried that again-no dice.
2. The noise will change in pitch if you turn the wheel to the right and hold the brake and tap the gas.
3. If you prevent the engine from rocking using an extension/block of wood etc the noise does not happen.
4. All motor mounts are in good condition.
5. It does not happen if you press the gas while holding the brake in reverse.
6. No noise at all going over bumps/rough roads.
7. The noise seems to be dependent on the engine tilting backwards.
The problem started about a year ago, when I was working as an advisor at a large toyota dealer. I took it in at that time, and my head mechanic looked at it for about 3 hours, couldn't pinpoint it and basically said "we can throw parts (http://www.toyotanation.com/forum/#) at it if you want, but i'd just drive it to be honest". I'm no longer working as an advisor, and the problem has gotten substantially worse. I'm hoping someone else has had the same or similar problem.
Thanks!