Occasional creaking noise AC

[200h]

initially i turned up to return the courtesy car but i checked the paint repair before i went in

and they had used a touch up stick as the repair i entered the building was greated

and told them i was going home in their car and to contact me when the car had been repaired properly.

that went down really well as you can imagine with that i cleared off and went home.

they did fix the rattle though.

 

[Thackeray]

On 4/24/2020 at 10:50 AM, Easterlily said:

To be sure, there is no damage done to it when the shifter makes this wobble then? I usually try to sneak when i release the brake slowly so that the movement speed is as minor as possible before the transmission locks it.

As the video shows, there's a fair bit of play in the parking ring - the slots are quite far apart compared with the grooves of the cog wheels. So the lever may have to slide into one of the slots, creating a bit of movement and the shifter may wobble, depending on whether the lever drops straight into a slot or not. This is normal on all automatic cars. But it seems like a good idea to release the footbrake gently so that it doesn't jolt into its slot too roughly. I hadn't thought of that - I might copy that if I remember next time.

 

On 4/24/2020 at 10:50 AM, Easterlily said:

is it recommended to hold the brake when changing the gear from D to N to R and/or vise versa or can you do these manouvers without engaging the brake pedal at all? given that the car is not moving if changing between D and R ofcourse.

Interesting question.  I've been driving normal automatics for many years and I think it's standard to hold the footbrake down while changing from D to R. I remember once riding as a passenger in my car while a mechanic tested it for a fault and he shifted from Drive to Reverse while the car was still moving, causing me to grit my teeth and hope he hadn't done any damage. On an automatic, the car is always moving if it's in Drive; it will edge forward even if you don't touch the accelerator.

On standard automatics, there are mechanical bits and pieces that move when you change the gear selection, engaging and disengaging clutches in the gearbox to select the gear. But on the Lexus/Toyota hybrid transmission, nothing mechanical changes in the transmission when you move the gear selector from Drive to Reverse. All the cogs are permanently engaged. All that happens when you switch from Drive to Reverse is that the computer switches motor/generator 2 (MG2) into reverse. So I can't think of any mechanical damage that might be done by not applying the footbrake while you change gear. The engine is not affected; it may keep running or it may stay stopped, depending what it was doing at the time. There is no reverse gear as such, the car is just driven backwards by the electric motor.

As for electrical damage, I don't know the answer. The other motor, MG1 is frequently changing the direction it spins, controlled by the computer, so my guess would be that MG2 would probably cope with being switched into reverse without any problem, too. I imagine the computer would be designed to protect it from any damage. If the car is nearly stationary it would be edging forward slowly, driven by MG2. If it then switches direction, I would have thought the designer would have made sure that it isn't harmed by excess current. But, as I say, this is just a guess.

Having said that, I'd suggest it might be a bad habit to adopt. That's because even if it was safe to do this on this type of hybrid car, it's probably not advisable on a normal automatic and if you adopt it as a habit, you might do it on some occasion without thinking when you're driving a normal automatic, which I'd suggest is not advisable.

As regards Neutral, it's important to remember that the high voltage Battery is not being charged when the car is in Neutral. So it shouldn't be used when the car is parked, for example, for the passengers to enjoy the view for any length of time - always put it back into Park. The motor/generators are disconnected when Neutral is selected but if the car is moved, they will spin nonetheless. This means the car should not be towed at any speed, as the motor/generators might be damaged if they spin at high speed. I imagine Neutral is only there to allow the car to be winched onto a trailer at walking speed.

 

[Easterlily]

2 hours ago, Thackeray said:

As the video shows, there's a fair bit of play in the parking ring.. 

 

Interesting info. I didnt know thr car could take damage while being towed. This must be a big disadvantage. Although i guess towing a 2015 electric car would be rare and probably due to a fatal crash anyway.

My biggest interest with my question is to put the car Into neutral when waiting at the traffic light instead of holding the foot on the brake. I guess i could switch the car into park but this would briefly turn on the reverse light when shifting and would look rather strange to the person behind.

[Thackeray]

33 minutes ago, Easterlily said:

My biggest interest with my question is to put the car Into neutral when waiting at the traffic light instead of holding the foot on the brake. I guess i could switch the car into park but this would briefly turn on the reverse light when shifting and would look rather strange to the person behind.

Don't put it into neutral at traffic lights - you'll be running down the hybrid Battery while you're in neutral instead of charging it, especially if you have air conditioning etc turned on. At worst, if you kept doing this, it might not start up again from the lights - though I expect you'd see plenty of warning messages before it reached this low level of Battery charge.

If you don't like keeping your foot on the brake you could put it in Park and ignore what the person behind thinks. But there's no wear involved in staying in Drive with your foot on the brake and that's how they're designed to be used, as are all conventional automatics. Just because you're used to putting a manual gearbox into neutral at the lights doesn't mean you need to do that on this kind of car!

[Easterlily]

54 minutes ago, Thackeray said:

Don't put it into neutral at traffic lights - you'll be running down the hybrid battery while you're in neutral instead of charging it, especially if you have air conditioning etc turned on. At worst, if you kept doing this, it might not start up again from the lights - though I expect you'd see plenty of warning messages before it reached this low level of battery charge.

If you don't like keeping your foot on the brake you could put it in Park and ignore what the person behind thinks. But there's no wear involved in staying in Drive with your foot on the brake and that's how they're designed to be used, as are all conventional automatics. Just because you're used to putting a manual gearbox into neutral at the lights doesn't mean you need to do that on this kind of car!

Yeah i guess so. Youve teached me so much! 😄How about putting the car in drive and engaging the handbrake. My guess would be that this causes wear on the brakes as the car keeps trying to push? As i guess the handbrake and footbrake doesnt work the same way?

[200h]

you do get a warning beep & msg telling you the traction Battery is getting low

and to put the car into P

this happened to me many many years ago whilst helping my partner

when she had a flat tyre and i nearly ended up with a flat Battery

[Thackeray]

49 minutes ago, Easterlily said:

How about putting the car in drive and engaging the handbrake. My guess would be that this causes wear on the brakes as the car keeps trying to push? As i guess the handbrake and footbrake doesnt work the same way?

I would guess you're right, though I don't know for certain. I don't think it would cause excess wear on the brakes as the car wouldn't be moving but it might cause wear to the electric motors, though maybe someone can correct me on this.

In a conventional automatic, the car does keep pushing when you have the footbrake on and the car is stationary. These hybrid cars simulate this because lots of people are used to it. But I'm pretty sure that when the hybrid car is stationary and you have your foot on the footbrake the car is using no energy and is not trying to move forward. It edges forward when you take your foot off the brake because this is what conventional cars do, and they've designed this one so it seems the same. There's no reason why it should begin to move when you take your foot off the brake - it's just that this is what most people expect if they're used to conventional automatics.

I suspect the parking brake is not the same. For example, if you leave the parking brake on when you put the car in Drive and you press the accelerator, the car will start to move but you'll hear loud beeping and a flashing light on the dashboard to show the parking brake should be released. The parking brake might hold the car stationary but I don't know if the car is attempting to move as it would be on a conventional car.

On a related topic, you may already know that you don't need to use the parking brake to do a hill start. If you stop on a hill and hold the car with the foot brake, the car won't start to roll back for about 3-4 seconds after you release the brake to give you time to start pressing the accelerator to move forward.

Incidentally, my air conditioning creaks too when the car starts up. I always assumed it was just making initial adjustments after registering current temperature and so on. I never attempted to have anything done about it.

 

[Easterlily]

55 minutes ago, Thackeray said:

..Incidentally, my air conditioning creaks too when the car starts up. I always assumed it was just making initial adjustments after registering current temperature and so on. I never attempted to have anything done about it.

 

Yeah. It seems to be a fair bit of people who have this 'issue' but neglect and leave it be. Maybe im just being picky although its a bit embarassing when new people enter your fairly luxurious car and and are met with fart noices. Maybe its just ironic. Anyway. Thank you all whove answered my questions and shared your thoughts. 

[Stempek]

Hi I have same problem with strange noise coming out from my ac , lexus Leicester said it won't be fixed under relax as is only noise bit is still works fine. Im not happy with that is anything what i can do about it ? I can pay nearly 3k and they can replace if i really want but relax rejected that as is still works os not failing. 

[wharfhouse]

18 minutes ago, Stempek said:

Hi I have same problem with strange noise coming out from my ac , lexus Leicester said it won't be fixed under relax as is only noise bit is still works fine. Im not happy with that is anything what i can do about it ? I can pay nearly 3k and they can replace if i really want but relax rejected that as is still works os not failing. 

Interesting that they won't replace under Relax - I guess if you are really serious about having it done you may need to contact Lexus HQ for a definitive statement on that - the dealers don't always know whether or not something is covered and just tell you what they think. However, as I reported earlier in this thread, if you are talking about the same noise, I have had it on and off on my car since I purchased it 6 years ago (it was 2 years old with 40K miles when I bought it) and it is now on 122K miles. The noise has not got any worse over that time and if it occurs it's usually on startup/shutdown when I think the ventilation flaps probably do a full range movement. To replace the flaps, it looks like it's probably dashboard out and that (as per you can see on this thread) may well bring more issues than you are trying to rectify... I don't recall anyone reporting a failure of the flaps on this forum to date - just the noise.