Noise From Rear Left Suspension?

[Dicomar]

Good evening,

Since the nice weather and the heat have come I started driving with the windows down, this made me realize just how good is the sound-proofing of the cockpit, but I noticed an annoying thing.

Basically when driving over bumps, potholes and speedbumps, I can clearly hear (only with windows down) a noise coming from the left rear wheel and only that wheel.

This happens at every imaginable speed, I hear a sort of metallic vibration, like something that is being shaken, and I guess it comes from the suspension or something connected.

I took the car to the dealer wich reassured me that everything is ok and the car is safe to drive, also they checked all the suspensions and have a new grease smeared on the brakes (something that would have being done anyway with maintenance in the future).

The chief mechanic and I went for a test drive and I let him hear that shaking noise but again he reassured me that it's normal.

Frankly for me this isn't a normal thing because it's the first time ever I hear a noise like that on a car driven by me and I'm not comforted by the fact that the noise is not present with windows closed.

Anyways, searching on google I found this: http://www.clublexus.com/forums/is-third-generation/700364-already-a-problem-with-my-new-2014-is-350f.html

They're talking about a noise coming from the parking brake cable and honestly I think that makes sense as I rarely use the parking brake (I just let the car in P) so maybe the cable needs to settle with use.

Yesterday I did the "trick" for about the 20 hours the car has been parked in the garage but I haven't noticed any difference so at the moment my IS will be in the garage, with the parking brake pulled, for another 2 days since I need it this saturday.

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Has anybody here experienced the same problem and can help me?

Apart from this issue the car is amazing and with mileage (1430 miles / 2300 km on the clock) I'm feeling it become more reactive, in Sport S/S+ mode the car is very quick! Also the e-CVT transmission is a masterpiece, nothing to do with Audi's multitronic (tested on an A5).

Thank you everybody.

[rayaans]

Ok take it to the dealer ASAP for a suspension check. There have been a few people in the states with leaky shocks producing a noise from their suspension which is clearly audible in and out of the car.

Keep complaining or the dealer wont do anything about the noise.

[Dicomar]

I thought that Lexus service was better than the other brands...they even checked all 4 suspensions...

Anyway let's see tomorrow if the parking brake trick miraculously has worked, then I'll come back to the dealer next week.

Thanks.

Ps. Any chance to retrieve a link to the American forum where they're discussing the problem? Just in case I'll need some extra information for the mechanics.

[rayaans]

http://www.clublexus.com/forums/is-third-generation/737967-rear-shock-leaking-at-9-000km.html

Here you go!

[Dicomar]

Thank you Rayaan, very kind.

One thing: I haven't seen nor oil residue under the car nor on the garage floor like they're saying in that discussion. I will check when I get back in the garage later.

Also I'll keep you all updated about this issue, after the week end I'll phone the dealer, and now I'm going to write on the Lexus Italy facebook page (they always answer to customers questions) just to inform them about the problem and see what they're going to say.

[Dicomar]

Update!

I've just driven the car for 30 minutes and, with my surprise, I noticed that the noise is ALMOST gone with the parking brake trick.

I drove on every pothole on the road at different speeds using all the drive settings from NORMAL to SPORT S+ and, where normally I would have heard the noise, this time it was gone.

To be fair I heard the noise a couple of times when passing on some holes but it happened when passing on 2-3 of them which were very close each other but I'm not able to say if the volume was lower or the same.

Now the car is in the garage with parking brake pulled and with a cardboard sheet under the left rear wheel, just to be sure there isn't any oil loss from the suspension.

Do you think that could really be the parking brake cable doing the noise at this point?

[rayaans]

Update!

I've just driven the car for 30 minutes and, with my surprise, I noticed that the noise is ALMOST gone with the parking brake trick.

I drove on every pothole on the road at different speeds using all the drive settings from NORMAL to SPORT S+ and, where normally I would have heard the noise, this time it was gone.

To be fair I heard the noise a couple of times when passing on some holes but it happened when passing on 2-3 of them which were very close each other but I'm not able to say if the volume was lower or the same.

Now the car is in the garage with parking brake pulled and with a cardboard sheet under the left rear wheel, just to be sure there isn't any oil loss from the suspension.

Do you think that could really be the parking brake cable doing the noise at this point?

It could be the parking brake if it hasnt been properly used. To be fair, my Mercedes C220 CDI has a parking brake problem and doesnt make any noises over bumps. I guess you will just have to see whether there is any fluid leaking from the shock and then keep us updated!

[Dicomar]

Update #1

The Cable trick has been a "placebo" For 1-2 days, the noise is still present.

I called the dealer and spoke with the chief mechanic who told me that apparently now all dealers are aware of the suspension noises as they recently have been informed by Lexus Italy.

At the moment they're checking the car in every area (even Engine) looking For suspect noises, suspension included.

If the problem is the rear suspension they'll Order the new piece under warrantly obviously.

When I'll be home I'll post the next update.

[Dicomar]

Update #2 and FINAL

The problem seems to be solved once for all, I hope.

So all the suspension are ok and there isn't any oil leakage, the mechanics checked according to a Lexus instruction bulletin, and in the end they found the source of the goddamn noise.

They fixed the parking brake shoes (not the cable), as it was indicated in a second bulletin, and from that moment the noise was totally gone.

We tested the car on every single pothole, bumps and rough asphalt at various speeds and with different spring stiffness (NORMAL --> SPORT S --> SPORT S+).

The work has been done in like 1 hour (inspection included), without an appointment, but since they haven't released me any document I can't post anything "technical" about the problem nor a scan.

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Basically, the known reasons (at the moment) are that this noise may be caused by:

1) Oil leakage from a suspension

2) Parking brake shoes

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Hope this will be helpful.

[DJP]

Many thanks Dicomar, you must be delighted and relieved the problem is sorted. Hopefully now you can get on and enjoy the car!