arrowroot

I have a 2016 RX350 FSport model. It’s now 3 years old and I have about 43,000 km on it.

Occasionally, when I come to a full stop at a red light (and remain stopped in Drive mode), I hear a rhythmic, low-pitch “tapping” sound coming from the rear of the car.

It seems to come from underneath the trunk area, but it is hard to pinpoint. The sound is hard to describe and I’m not sure if it is better described as a low-pitch “tapping” sound or a low-pitch “creaking” sound.

The sound doesn’t occur all the time. In fact, in most cases, I don’t hear the sound at all. But once in a while, I’ll hear it when I come to a complete stop, and it might continue for a few seconds, or it might continue until I release the brakes / start moving again. It seems to go away right away after I release the brakes.

Has anyone else experienced the same?

What could be the problem here?

It is almost impossible to replicate predictably, as it happens randomly and only very occasionally.

.

ravenuer

Agree this is a tough one. The only thing that comes to mind is something metallic (exhaust system?) is either heating up or cooling down.
Perhaps you could replicate it in your driveway with someone getting down there and see something. Just be very careful!

kmiller882

Go to the dealership and have them check your rear-hatch lock assembly. Mine was malfunctioning and trying to lock over and over from time to time which produced a wierd clicking sound. You may be hearing the same thing.

arrowroot

Thanks i will. Although it sounds like it’s coming from under the car.

Was the sound that yours was making a slower rhythmic sound?

The sound I’m hearing is somewhat rapid, about 2 beats per second.

kmiller882

Ah, well then yours may not be that part. My clicks were spaced about 10 seconds apart on average. I originally thought my rear wiper was malfunctioning but I was able to get it to do it one day when I parked in my garage and after listening in every area near the rear (much to my neighbors amusement I'm sure) I was finally able to isolate it coming from the hatch.

arrowroot

The sound happened again today, and persisted long enough (as long as I remained stopped) for me to get a few videos.

Here are 3 videos of the sound (#1 was taken inside the cabin, #2 and #3 are taken from outside the car). As the engine is running, you can hear the continuous dull tapping noise.

Here are some other things I've noticed about the noise:
- The sound doesn't occur every time the car is stopped.
- If the sound occurs, it sound persists as long as the car is stopped and goes away when I start accelerating.
- The sound seems to happen more frequently when the entire car & engine are warm.
- The sound seems to happen more frequently when the car is stopped on a slight upward incline.

You can hear the sound on top of the normal engine noise in each of these 3 videos:

Video #1: Taken from inside the cabin (I open the window halfway through the video)
https://drive.google.com/open?id=15J...vSbdtjdd2RGX2e

Video #2: Taken from outside the car
https://drive.google.com/open?id=1BI...89O6OQi5y1WYgS

Video #3: Taken from outside the car again
https://drive.google.com/open?id=1nC...d2dmI1Z9uSC7_H


Thanks for any tips.

GSFRX350

Hard to hear well, but I'm thinking there's a fuel pump there could be that. Someone else on here may know.

kolokmee

What's your fuel level when you hear that sound? It sounds a little like my 450h a couple of times when I let the fuel level go down to when the warning light comes on and the ICE kicks in. It went away after I filled up, so it might have been bad gas, or fuel pump.

arrowroot

It was a full tank in this particular case (full and not overfilled).

I can't recall if the sound occurs when the tank is halfway or empty - I will try to pay attention and let you guys know.

To be honest, I can't tell if it's a "tapping" sound, or a "gurling" sound, or a "rattling" sound. It's a noise that sounds like it shouldn't be there (as you can hear in the video).

stevemcb

I have the exact same sound and it started after I had the exhaust mod done. I took it back and they said all is fine with the exhaust . It only happens a certain times and I also recorded it. I am 99% certain it has something to do with the exhaust pipe or muffler maybe even internally.

arrowroot

Interesting... I’ve never had any exhaust modifications on my car.

stevemcb

I had the TSB done for the droning sound. It started after that. I have recorded it. It will get worse and then I will take it in . They will say they hear nothing when you take it in.