Clicking Noise Under Acceleration ('02 Rx300)

[Monnone]

My wife's RX300 has a problem I'm not certain I can figure out. There is a moderately loud clicking sound that seems to be getting worse in the front of her RX. I have a couple of suspicions but they don't seem to fit this noise completely. Let me explain it the best I can:

First things first as it could matter, the ONLY major work we have done to her RX is the transmission. It had to be rebuilt...like so many others I'm aware of for this model. I take pretty meticulous care of our cars and turn my own wrenches. I stay on top of the oil changes, fluids, tires, brakes and other maintenance items. Have been for 20 years with my own cars.

The noise sounds like a clicking/clanking/rattling noise. It gets louder under acceleration then quites down as speed is reached. While accelerating the noise sounds like the lifters are shot. But again, the noise quites down a bit when speed is leveled out but not 100% gone. It will come and go.

Things I've tried to isolated the problem:

- With the transmission in Park while revving the engine, there is no noise.

- With the transmission in Neutral while driving and revving, there is no noise.

- With the transmission in Neutral while turning, there is no noise.

- The only time the sound is present is under acceleration while the transmission is in Drive.

This seems to rule out, CV joints, bad lifters, or even bad knock sensors but I could certainly be wrong. I first thought it was a strut mount or even one of the struts until the noise starting getting more repetitive and louder (which worries me).

Any advise would be greatly appreciated! I'm a little nervous to have her drive it at this point until I figure this out.

Thanks you!

Brian

[intakerGS]

Perhaps a long shot, but it does remind me a bit to this thread: rattling noise (see bottom solution). There are also some sound files to verify.

[Monnone]

Thanks for the reply but the clicking does not sound like this. It only occurs while its in Drive and under acceleration. Again, it sounds like a rapid loud ticking noise but it does not happen while the car is in Neutral even revving. Seems like the Transmission must be engaged in order the tick to be heard.

Also, while starting from a stop it sounds like the tick repetition starts slowly and then gets faster. As speed increases the noise quites down.

Any help is appreciated!

[Monnone]

Drove her RX again. The sound seems to be intermittent. It also sounds loud at times and quieter at others. It's really starting to sound suspension or wheel related. Anyone have any thoughts?

[lenore]

Still could be the CV joints, under load causing the click...Wheel bearing? ABS sensors going bad...? Keep us posted

[Monnone]

I might be thinking CV joints too. Usually you hear that during turns though right?

[NewEnglandLexus]

Any update on the cause?

Have the motor mounts been changed? Have read posts where a bad mount causes engine to shift when under load - leads to a clicking noise.

[DanielJ.K]

I have a 2002 Lexus RX 300. Got the car from my step mom, its a grocery getter with 99,000 miles on it. Drove it everyday and by 140,000 miles the tranny broke. Got that rebuilt now, my noise started out seeming to be an exhaust issue. It would only do it between 32 and 40 miles an hour. Also side note my breaks started to feel like there was some air in the system. My girl and i are broke so had to keep driving it so now its a rotating clunking noise that is fairly loud and you can feel it through out the car. It happens at almost all speeds now! Ugh. Exhaust manifold, drive shaft, tranny, whats the problem!

Edited September 8, 2021 by DanielJ.K