RX711

2004 RX 330 106K Miles

Symptoms: Muted thump sound. Not sure if it’s muted because of the insulated cabin. But I drive with the driver’s side window open and can hear it. Seems it’s coming from the left front or just the front. Because I drive with the window open it were on the right side I think I would notice it.

This happens sometimes when going down say a driveway ramp (not steep). I can climb a hill and not hear it. Happens sometimes say when the vehicle tilts a bit on a turn where the pavement is sloped or uneven. Seems to happen only in low gear i.e., at really slow speeds. Can happen on first drive of the day when taking off after being parked on the street. Have heard it sometimes if let off the accelerator. I cannot isolate when and in what situations because its inconsistent. But I have heard it in the instances described above.



So what is it? Motor mount? Brakes? Transmission? Nothing to worry about?

Im not sure if its related but one day I drove home, rolled into my parking space on the streetand heard a loud pop like the car rolled over a balloon filled with air. I’m not saying it actually did as I never figured out if that noise was related to the car. I looked under the car the next day and saw nothing. I looked at the space on the street where it was parked and saw nothing. So I concluded it came from somewhere else unrelated to the car.

This noise may or may not have started after that. One day I drove around with the radio off and noticed the thump and it has stumped me in terms of where it’s coming from!

Thanks in advance!

05RX330AWD

Start by verifying the struts, they can be weakening....
had a thump in the rear, no struts leaking although one was weak & eventually leaked later.
Replaced the struts, no more thump.

LuckyPants

When I bought my previous RX (same year and almost same mileage as yours is now), it had a worn out sway bar link that would thump/clunk when I drove over bumps or uneven roads, or pulled into the driveway. I'd check those first since they'd be cheaper than new struts. I replaced mine myself, but had a heck of a time with the rusted bolts and way over-torqued lug nuts.

Here's the thread about it: https://www.clublexus.com/forums/rx-...f-vehicle.html

kalcris

I have the same issue - right side, sounds like middle/rear. replaced rear struts, sway bars and mounts, still there. I did notice that there are 2 brackets on the exhaust that are rusted out. Doesn't seem loose and can't make it thump by pushing up on it. Right front boot is torn (per link above) but no sounds when pushing down on it.

HtownBlue

Control arm bushings.

RX711

I'm beginning to conclude this always happens when at cruise speeds and I let off the gas pedal fast. If this were a manual transmission I would say it happens only in first gear. If I stay on the gas accelerating into 2nd gear etc. speeding up it does not happen (or I don't hear it). The thump is more consistent in such scenario then when the vehicle tilts. I also thought I heard it happen when making a tight turn but have to test that again.

Other than this, my RX runs very smoothly and no other unusual noises or issues at all.

Anymore feedback would be much appreciated. Really want to pinpoint this. Thanks in advance.

RXGS

iTrader: (2)

Had a similar noise, was the flange/doughnut/gasket thing between the front pipe and mid-pipe causes the two to hit one another when the engine torqued under acceleration or on sharp terms.

RX711

Thanks, do you mean exhaust pipes?
BTW If I put the car in neutral and step on the gas, I don't hear anything. Wouldn't that be similar to acceleration?

RXGS

iTrader: (2)

Yeah and mine would only do it in drive, put in drive, foot on gas and break and press the acelerator and see if it does it then.

RX711

Thank you to everyone who chimed in and also to those who read the thread and considered my case. I brought the car to a different mechanic today as made a hard turn at race track speed and it was really loud (really loud). Turns out one of the motor mount bolts was not even tightened when in for other service some time ago. Seem the regular mechanic was lax. Its hard for me to understand how someone could let this happen. In fact I am f ing pissed that they were so careless.

After the mount was tightened down I experienced none of the thump noises previously described.