LEMMON714

Hello all,

New member here...

Recently my 2015 RC350 f sport developed a rattle that's driving me crazy...It feels like it may be caused by suspension since it only happens when going at speed over bumpy roads. The faster the speed, the faster the rattle. It doesn't happen when going over speed bumps in parking lots. It started happening after I got the car back from a oil change and pads/resurface. I brought the car back and the dealer said they dissembled the pads and rotors, adjusted cross member, all shocks and brake studs. After driving to work today, it's same issue, not better or worse.

Just wondering if anyone else has had a problem like this? car is 23000 miles so it shouldn't be any normal wear and tear. It sounds like its coming from the front driver wheel to hood area.

any feedback would be appreciated!!

thanks!

sharvin3RC

New member here as well? I'm personally not experiencing this issue or ever heard of something like this at 23k miles. Maybe something that happened at the dealership.
I'd take it straight back to the dealer and talk to them about it. Should be covered under warranty as well, if there something that is broken.

-Sharvin H.

rcJten

My car developed a rattle that sounded as though it was coming from the rear suspension. Turned out to be the parking brake assembly needing adjustment and grease. No rattles since .

rmason

I'm having the same issue. It sounds like a muted clunk under the hood and audible in the cabin while driving. It's not to the point where it's doing it constantly but over less than perfect roads, it's there for sure. My first round of request for checkup came back "unable to duplicate". Have a scheduled appointment with the master tech in the morning, I'm making sure he gets to listen to it before dropping it off. I'm guessing it's going to be one of the following in the order of likeliness: strut mount, motor mount dog bone, ball joint, a sway bar link or a loose hood mount. I'll report back and see what they find.

LEMMON714

Got the car back last week, they finally fixed the noise. Took a test drive with one of the managers and he was easily able to replicate the noise. It ended up being the brake pads they replaced the previous time they had the car. The service writer told me they were off by "a little bit", whatever that means. I don't think he cared enough to know what was going on to give me a detailed answer. The service ticket I got back said they replaced the pads again.

rmason, does the noise stop when you apply brakes? When I drove the car with the guy from dealer we figured out the noise go away when applying any pressure to the brakes. We found a really bumpy road next the dealer and just kept going back and forth and kind of pin pointed it to the brakes, plus the fact that it was the last thing they touched, they were able to find and fix the issue pretty quick this time.

Anyways good luck to you

rmason

The possibility of pads making such rattle never crossed my mind so I never attempted to replicate under breaking ...vehicle brakes fine so squeals or anything under braking.

I had two types of noise though...one was under the hood like a loose hood latch sound and the other coming from the suspension area like a kick on a tool bag when going over bumps.
I got an update on the status and the have found that the breaks pads on the vehicle were not factory so they are swapping them out to factory spec. They also tell me they found both front struts or strut mounts bad and are replacing those as well.

Should have it back by Wednesday so we'll have to see.

Thanks

rmason

update: 1) they have discovered noise coming from front strut and found them leaking so replaced both front strut assembly. 2) They have discovered that the other lexus dealership has installed IS/GS pads instead of pads for the RC which according to the tech will rattle due to a bit of play as it sits on the caliper. Hence, rotor and pads are being replaced to spec.

final: These are the tech notes: "TEST DROVE VEHICLE WITH CUSTOMER AND CONFIRMED NOISE. FOUND FRONT SHOCKS TO BE SEEPING CAUSING THE NOISE 430151 430151A REPLACED FRONT SHOCKS AND STRUT TOWERS NO NOISE AFTER REPAIR." " ALSO HEARD NOISE CONFIRMING CUSTOMERS CONCERN CAUSED BY THE FRONT BRAKES. RECENTLY FRONT BRAKE SERVICE WAS PERFORMED AT LEXUS OF ****** AND WRONG BRAKE PADS WERE INSTALLED. REPLACE FRONT BRAKE PADS, SHIMS AND ROTORS. ALSO INSTALLED A SHIM BETWEEN THE HUB ON BOTH FRONT LEFT AND RIGHT."

Good as new. Hope this helps others with similar concerns.