Noise diagnosis is hard in your case because the rumble is NOT constant and only occurs at low speed/low RPMs. I will give some suggestions about the rumbling noise relating to the gas/ICE engine. I will leave it to others to give suggestions relating to the hybrid systems and eCVT. There are two main diagnosis for rumbling noises like in your audios: 1. an exhaust leak, 2. an air/fuel mixture imbalance. If the gasket between the primary catalytic converter (which is up near the firewall welded to the end of the exhaust headers) and down pipe has failed or there is a pinhole or hairline crack in the exhaust headers it could make that sort of noise--but I would expect it to get louder when the ICE is running and accelerating at higher RPMs and stay constant. An A/F ratio imbalance could make an intermittent rumble. It could be caused by many things. Your rumble might be caused by the top of the air box not being clipped down properly or the big tube going to the throttle body being loose--you could be hearing an air intake roar or rumble at certain RPMs and engine loads. I'd want the dealer service tech to run a Techstream scan for all DTC codes. This is always the first, basic step for any engine issue.

 

Thank you for this, it's actually very helpful.

The noise only occurs when the ICE is running so I'd assume what you've written here applies to my engine as well, despite it being part of the hybrid system.

Re the techsteam, would that be able to pull anything useful if no errors (eg. check engine light) and being displayed on the dash?

My next step will be driving with a tech to show them the noise in person. Would I want some diagnostic tool plugged in while I'm driving?

Thanks again!

 

Re the techsteam, would that be able to pull anything useful if no errors (eg. check engine light) and being displayed on the dash?

My next step will be driving with a tech to show them the noise in person. Would I want some diagnostic tool plugged in while I'm driving?

There are MANY gas engine and hybrid system problems that do NOT light up the CEL. In RAVs, sometimes you get warning messages on the MID instead of trouble lights, sometimes no warnings or lights even if there are DTCs. Techstream finds ALL DTC codes in every module (computers--I think 32 of them in RAV4s). The Techstream or an aftermarket, advanced, expensive scan tool can indeed be plugged into the OBD2 port while driving for diagnosis--though that is usually not necessary. If the problem is something like a cracked exhaust manifold the Techstream may find a code for the air/fuel mixture being incorrect; or it will find a problem in the long term or short term fuel trims, or in the downstream (after catalytic converter) O2 sensor. Some hardware issues--like wheel bearings, CV joint--that can make rumbling noises are not diagnosed electronically by Techstream. Those things are diagnosed by an experienced mechanic listening while riding in the car and following up with hands on physical tests (spinning the wheels with the car on a lift for example.)

 

Any snow messing with the exhaust or damage from snow? Any way to recreate the noise in neutral to eliminate the driveline as a possibility?

 

No issue with the snow/damage. We first started noticing the noise in the fall.

Hard to say if I can recreate it in neutral, it usually happens while I'm in motion. I have a video of me going up and down the revs while in neutral and you can hear the tone shift into something deeper.

Video

 

There are moments when you can achieve those speeds with propulsion done by the battery only if you look at the power meter. This would be key to rule out the engine and the exhaust and to focus on the driveline if the noise is present without the engine running. I assume the engine has to be involved for the noise then. Tough one for sure. Perhaps, a pro needs to use chassis ears or something.

 

I see what you mean. It's 100% when the ICE is running. The car is whisper quiet when it's using the EV.

 

The Toyota D4S fuel injection can make the engine intermittently clattery, almost diesel-like. When it switches from port injection to direct injection, it gets noisy. It almost sounds like something is wrong, but it’s normal. A friend‘s new Tacoma does the same thing.
Not sure this is what you’re experiencing, but it could be.

 

The Toyota D4S fuel injection can make the engine intermittently clattery, almost diesel-like. When it switches from port injection to direct injection, it gets noisy. It almost sounds like something is wrong, but it’s normal. A friend‘s new Tacoma does the same thing.
Not sure this is what you’re experiencing, but it could be.

Not sure if this is quite the same. The car never made the noise for the first 10,000km or so, it's just over the past few months where it started

 

The eCVT is just electric motor and a gear box, it shouldn’t make noise.

 

To clarify, two electric motors, MG1 and MG2.

 

The Toyota D4S fuel injection can make the engine intermittently clattery, almost diesel-like. When it switches from port injection to direct injection, it gets noisy. It almost sounds like something is wrong, but it’s normal. A friend‘s new Tacoma does the same thing.
Not sure this is what you’re experiencing, but it could be.

In video 3 if you can focus on the rough engine noise you'll notice that it stops about half way throughout then it starts back up in a sort of sputtering fashion. That all happened on a straight smooth road. The noise happened when I was feathering the gas, and went away when I pressed a teensy bit harder. I can also feel the vibrations of the noise in the gas pedal when it happens.

Sounds more and more like the direct injectors as nels says.

 

NO it is NOT direct injectors! They and the high pressure fuel pump mounted on the engine make clattering, clicking noises. If you listen to the OPs audios and videos it is a low continuous hum or rumble--not a clatter. Also as OP says he's had the RAV for a year and he's familiar with the normal noises and that hum is a new and different noise.

 

I think it is okay not to say anything if you don’t know. There is no shame in that. But to make wild theories when you have no clue is not so cool in my book.

I'm not making up any wild theories. Diagnosis of car noises is a guessing game--you speculate and rule things out. I asked knowledgeable hybrid aficionados if the eCVT could be making that hum or rumble. As I said in post#2 I was only diagnosing the ICE and leaving it up to others to speculate about the eCVT and hybrid components.

. I will give some suggestions about the rumbling noise relating to the gas/ICE engine. I will leave it to others to give suggestions relating to the hybrid systems and eCVT.

 

I realize this is hybrid rather than ICE but could it have any commonality with the heavy growl noise I experienced when temperature dropped. A lot of the symptoms seem common. Have a look at the discussion in the link below

https://www.rav4world.com/posts/3066140/

 

I realize this is hybrid rather than ICE but could it have any commonality with the heavy growl noise I experienced when temperature dropped. A lot of the symptoms seem common. Have a look at the discussion in the link below

https://www.rav4world.com/posts/3066140/

This does sound a little promising. The only thing that gives me pause is that the engine started making the noise when it was warmer outside. I'd say ~10°C back in early Nov which was uncharacteristically warm around these parts.

Funny enough, it was my wife who first pointed out the noise and a cold car was the first thing I assumed, but I ended up ruling this out due to it popping up in warmer weather/even after the car has been driven for ~2hr+ straight.... That said, I'm open to revisiting the cold issue, I've got 3 years warrenty on this so if all else fails, I can wait til the summer and see if it goes away

As an aside.... I WISH the 2023 Rav4 hybrid would show rpm so I could be more specific. All I have to go off of is a charge gauge and a fuel efficiency gauge
-_-

EDIT: Totally forgot to mention, I've had the opportunity to drive In few Rav4 hybrids during this period and none have had this issue.

 

to me it sounds like a vibration rumble
two things rubbing/vibrating together
could be anywhere


but that is what is sounds like, physical vibration between
parts normally separated by more space or vibration damping gasket

at any rate time to get the microphones and isolate the source
keep moving the mic, recreate rumble, move mic, repeat until
you find it

beg/borrow/steal something
Auto Diagnostic Listening Device, Sensor Probe, Sensor Clamp with Lead

they can be expensive or cheap

Amazon.com

 

In sympathetic resonance the surface emitting the noise may not be what is causing the vibration. I am just home from a plus 200 mile trip. A few degrees below 0 F. The noise is still there but now that I have eliminated the worries about something about to self destruct it is not nearly so bothersome. My XLE has a tach. and the noise is focused between 17 and 1800 rpm at modest throttle. That is just shy of 60 mph on a slight uphill. On the level at that speeed it upshifts a gear and drops the revs below the noise range.
Off topic, but on a cold day like that gas mileage is off by a bit more than 10%

 

Sounds a wee bit like an exhaust manifold/ EGR leak to my ears but there's a couple of other things worth a check.
firstoff, does the noise change depending on whether aircon is on or not?
secondly, throw a dose of your favourite injector/fuel system cleaner in the tank and report back after a few days.

It might well be just a resonance of some kind tho- there are various mass dampers around the vehicle and some are on rubber mounts; this rubber will respond differently when it's btterly cold...

 

Having the RAV4 Hybrid 2024 for about 1000km now, new car. I noticed the engine gets noisy at low rpms and I think nels0300 is right in his statement. And I also think it has to do with a colder outside temperature.