Just Bought Used Rx400H, Questions For Other Owners

[mctufts]

Hello,

First time posting on this forum as I just recently bought a used 2006 rx400h with 40,000 miles on it and a clean title history. I love driving it and there have been no major issues but I did have some questions for other owners since this is my first hybrid vehicle.

1) I've read on other threads about the high pitching whirring sound of the regenerative brakes. Although I don't find it particularly annoying, it is somewhat louder than I would have expected, not only on local roads and low speeds but on the highway when braking as well. Is this normal?

2) When going from accelerating to coasting, after about 1 second into the coast or so, I hear what sounds like the distinct whirring sound of the regenerative brakes kicking in for about 1 second before going away. I also feel as though there's a slight but noticeable decrease in speed during this period more than you would expect from just coasting without braking. Again, this sound only lasts for about a second or so soon after I start coasting. Has anyone else experienced this? When I asked the technician at my dealership, he explained that this is normal. I can't quote him exactly, but he mentioned it had something to do with the sound of the electric motors turning into generators to send energy to the Battery (noted in the hybrid manual), which would also cause a slight bit of drag.

3) Being a used vehicle, I expected some creaks and moans but I just wanted to see what experiences others have had with these types of sound. On a test drive with a technician, he confirmed some of these sounds as being abnormal and fixable, such as what he described as a "sticky" sound coming from the back seats, a sound from the rear hatch, and high pitched squeaks coming from the brakes when completely stopped but varying the pressure on the pedal. He said he should be able to eliminate all those sounds. I think there were some TSBs released for the last two but has anyone experienced anything like "sticky" sounds from the seats or elsewhere? I've also noticed what sounds like a "sticky" sound/creaking sound from the front dashboard passenger side.

Anyway, thanks in advance for any opinions or insights. I'd greatly appreciate it!

[Duncan Roberts]

Hello,

First time posting on this forum as I just recently bought a used 2006 rx400h with 40,000 miles on it and a clean title history. I love driving it and there have been no major issues but I did have some questions for other owners since this is my first hybrid vehicle.

1) I've read on other threads about the high pitching whirring sound of the regenerative brakes. Although I don't find it particularly annoying, it is somewhat louder than I would have expected, not only on local roads and low speeds but on the highway when braking as well. Is this normal?

Never had this.

2) When going from accelerating to coasting, after about 1 second into the coast or so, I hear what sounds like the distinct whirring sound of the regenerative brakes kicking in for about 1 second before going away. I also feel as though there's a slight but noticeable decrease in speed during this period more than you would expect from just coasting without braking. Again, this sound only lasts for about a second or so soon after I start coasting. Has anyone else experienced this? When I asked the technician at my dealership, he explained that this is normal. I can't quote him exactly, but he mentioned it had something to do with the sound of the electric motors turning into generators to send energy to the battery (noted in the hybrid manual), which would also cause a slight bit of drag.

Never had this either

3) Being a used vehicle, I expected some creaks and moans but I just wanted to see what experiences others have had with these types of sound. On a test drive with a technician, he confirmed some of these sounds as being abnormal and fixable, such as what he described as a "sticky" sound coming from the back seats, a sound from the rear hatch, and high pitched squeaks coming from the brakes when completely stopped but varying the pressure on the pedal. He said he should be able to eliminate all those sounds. I think there were some TSBs released for the last two but has anyone experienced anything like "sticky" sounds from the seats or elsewhere? I've also noticed what sounds like a "sticky" sound/creaking sound from the front dashboard passenger side.

The squeaking from the leather means that the leather needs feeding - two adjacent pieces rubbing together. You seem fixated with the brakes - never had such issues. The dash board as well is odd.

Hate to say it but this car seems either a bit of a dog or you are supersensitive.

[mctufts]

Agreed to the supersensitive comment. I believe that definitely is a factor in my hearing of some of the more minor sounds, ie, the dashboard sounds. Still, on a test drive with a Lexus technician, it was he who described the "sticky" sound of the back seats and mentioned that it could be fixed.

As for the whirring sound when braking or even just coasting, that's good that you have not experienced them. Unlike the other sounds described this sound is consistently present and easily reproducible for me. At this point, two different technicians have explained that the sound is normal as theTransaxle regen braking system basically turns into an alternator to generate electricity. While that explains the characteristic regenerative braking sound, I'm still not clear as to why it seems to occur without input from the brake pedal when coasting.

In any case, thanks for the input. I'll just turn up the music system or something to drown out those other sound in the future!

[Duncan Roberts]

Agreed to the supersensitive comment. I believe that definitely is a factor in my hearing of some of the more minor sounds, ie, the dashboard sounds. Still, on a test drive with a Lexus technician, it was he who described the "sticky" sound of the back seats and mentioned that it could be fixed.

As for the whirring sound when braking or even just coasting, that's good that you have not experienced them. Unlike the other sounds described this sound is consistently present and easily reproducible for me. At this point, two different technicians have explained that the sound is normal as theTransaxle regen braking system basically turns into an alternator to generate electricity. While that explains the characteristic regenerative braking sound, I'm still not clear as to why it seems to occur without input from the brake pedal when coasting.

In any case, thanks for the input. I'll just turn up the music system or something to drown out those other sound in the future!

If you look at the power display you will probably find that it is charging even when coasting.

[Boxbrownie]

The creaking dashboard is a well known issue, it happens when small insulating pads break down and enable the dash to move relative to the body structure, unfortunately its a very expensive dash out job, but can be cheaply fixed by forcing a small wedge of foam into the gap between the dash and windscreen/body area, trial and error mostly.

The "braking" sound is the regen unit charging and will happen when coasting as well as braking, obviously you have more sensitive hearing than some

Last time I drove a 400H the regn unit reminded me of the sound a London Underground train makes.....luckily the Lexus is a lot more comfy though

[MikeyB100]

You car sounds pretty normal to me.

I had the creaking/sticky noises from the rear seats when I bought my car recently as well. It went away when I folded the centre armrest down (I don't need 5 seats, otherwise I'd be looking for a better solution).

The whirring noises sound typical - my car does the same. You get used to them.

As for rattles etc, I have one that comes and goes from somewhere in the tailgate. I'm too busy to get it looked at by a dealer - do I gather it's fixable under warranty?

[GD1]

Got to say I think your brake noise sounds pretty normal to me as well. I thought something might have been up with ours, but I've heard others when in car parks making similar noise.

I'd describe it like a very, very faint brake squeal - difficult to hear, but certainly there!

As for the noise in the rear, as mentioned above, that's probably the rear arm rest between the seats - use a leather cleaner and conditioner (something like Gliptone's Liquid Leather).

Cheers.