I've noticed some things with the Lexus GS 450h that I'm not accustomed to experiencing, which it's my understanding all are perfectly normal with the hybrid:

The occasional clank noise coming from the rear
The air movement noise - a turbulent rushing sound of air when the cooling fans for the traction battery come on.
I was adding POIs in the NAV and letting the car run at idle when suddenly I felt the car's body move in a twisting fashion like a large inductive motor was energized and torqueing the entire car.
All common things according to the owners manuals...

I'm sure there will be other things I'll experience that I'm not used to.

 

Very interesting observations.

I don't hear any sort of "clank" noise from the rear (or anywhere really). My car is dead silent, besides the obvious road (tire) and wind noise, but it's very quiet as compared to other Toyota vehicles that my family owns.
Edit: I came across this topic. Is this what you're experiencing? https://www.clublexus.com/forums/gs-...-rear-end.html

Regarding the traction battery cooling fans - I don't think that I've ever heard them! But then again, I don't sit in the rear seats. Are you hearing these this while your vehicle is stationary (i.e. in Park and while you're messing around with the POIs/navigation)?

The only one that I can relate to and confirm is that the last point about the body move/shimmy - that happens to me when I run my battery runs low: Let's say I'm waiting in a grocery store parking lot and leave the car started in Park, once the battery level gets low enough (probably like 1 bar, I haven't tracked it), then I will feel the vehicle's ICE kick on and shake the car a bit as it attempts to charge the battery back up to a reasonable level. Is that what you're describing?

If you could capture video/audio of the first two points (the clank and the traction fan noise), I would be interested in hearing from others if it's a common noise experienced by others or if it's unique to your vehicle.

Regards,

~ Im2bz2p345

 

The 'clank' noise is even mentioned in the Owner's Manual Quick Guide on page 14 and in the Owner's Manual on page 68 under 'Sounds and vibrations specific to a hybrid vehicle - with specific to the clank noise I referenced - states the following; "Relay operating sounds such as a snap or soft clank will be emitted from the hybrid battery (traction battery), behind the rear seats, when the hybrid system is started or stopped.

I suspect the sensation that something with moderate weight has slide in the trunk toward the rear seats is the hybrid system starting. All perfectly normal...

There are many other items under the 'Sounds and vibration' category (e.g. brakes, fans) but the 'clank' sound seems to be what you are most interested in hearing/learning more about. It all sounds (excuse the pun) perfectly normal! I'll soon get used to the unusual sounds and vibrations.

I have noticed that the brakes have a somewhat different and distinctive feel at near-zero speed, which I presume is likely associated with the regenerative feature. Again, all perfectly normal...

I'm one of those people that are very sensitive to changes and various noises. I can tell the difference in 1 or 2 psi tire pressure, and I hear mechanical and electrical sounds (e.g. diodes, triacs, relays, electro-magnetic, capacitance discharge, r/c networks, etc.) that most people simply don't hear. I even tend to visualize the mechanical operation of things (e.g. engine (valves, pistons, solenoids, etc.) and transmission and brakes, etc. as I'm driving. I know - strange huh!

 

On my 2016 I have none of those noises... Though I am still on a mission to track down if the weird high pitched ringing sound my car makes at walking speeds is part of some pedestrian warning system.

 

I believe it is. This is a topic from the ES hybrid, but it talks about the same vehicle is running on electric battery high pitched sound. Toyota/Lexus refers to it as the "Vehicle proximity notification system": https://www.clublexus.com/forums/hyb...on-hybrid.html

~ im2bz2p345

 

I never hear any fan sounds in my GS. On my CT I could hear them all the time. The torque when starting the ICE is bc it's the traction motor starting the engine I believe. That's a big starter!

 

I noticed (at least with stop-n-go city driving) that the traction battery is pretty quick to discharge but also pretty quick to recharge. I don't know quite what to think of that. When the traction battery is near full charge at 6/8 or 7/8 it doesn't take much longer to discharge it down to 2/8 versus when the battery started at only 2/8 or 3/8. In other words, starting with a higher percentage of charge doesn't really gain you anything much the way I see it. . It seems like the traction battery and motor are hiding its contribution. The battery drains rather quickly but likewise it doesn't take all that much to bring it back up to a high percentage of charge - but what does starting at a high percentage of charge really get you?. It's like pouring a gallon of water from a big container while at the same time a gallon of water is being poured into the big container. You haven't lost anything but you haven't really gained anything either. Take a little, give a little - and so on, and so forth. No harm, no foul. Six in one pile, half a dozen in the other. Travel up a slope and travel down a slope of equal grade and distance. The traction motor and battery are contributing but in such a way that it's difficult determine how much it's contributing. Viewing the 'Energy Monitor' only tells you which source of energy (the motor & battery or the ICE) to powering the vehicle.

Clearly the combination of traction motor and traction battery is contributing to save fuel used by the ICE, I'm not doubting that. I just wish you could see the benefit of the traction motor and battery compared to the ICE a little better. Maybe something like displaying the percentage of time the traction motor was used versus the ICE. And, display the equivalency of the traction motor used to gallons of fuel actually saved. If I go on a 500 mile trip I'd like to see how much each source of energy (electric motor vs. gasoline engine) contributed - not just when they contributed.

It's quite different from say an iPhone battery or a power tool battery where you can actually see how much performance you're getting from the battery and phone, or from the battery and tool, by how much work it can do over a period of time - and/or how much time it takes the battery to discharge to a level in which it can do it again.

 

Does the clank sound happens when the ICE turns off and transition to EV?

If so, the fluid pressure points in the dual stage eCVT needs to be relearnt as the hydraulic operates break 1 and break 2 in there.

 

I've only heard a distanced (muffled) snap one other time I think. The snap sound is muffled and only slightly heard the one or two times I've heard it. It sounds like a rather small electrical relay or contactor making or breaking its contacts as the coil is energized or de-energized. It's not really a clank. The owners manual describes it as a 'soft clank' or snap.

The clank sound I heard may have actually come from the failed rear AVS shock I needed to have replaced.