Have you guys ever heard this noise from the suspension when going over bumps w/ the windows rolled down? It's loud enough to where i am sure it could be heard if you were a pedestrian walking next to the car. I have an IS350 Fsport (AVS), sounds pretty junky.

 

Miles?

Speed?

Rear or front suspension?

 

front, 1650 miles, city speeds over bumps

 

Have you taken off the wheel on the side that is hitting and looked to see if anything was marked or looked bent?

My guess would be that you have a shock/strut damaged. Or something is slightly tweeked and you're hitting off something in the proximity of that part. I apologize for the vagueness. I would with as few miles as you have, I would recommend a trip to the dealer to ask whats up. They will probably warranty you a new part if something is damaged.

That is one thing that does upset me about my wife's new IS. It is wonderful for normal driving, but sounds like Scion quality when it hits holes in the road.

 

Do a quick search - I think I recall some people having this noise and they fixed it by setting the parking brake for several days in a row. It had something to do with slack in the brake line.

 

thanks all, ill try that parking brake trick first. ..it sounds more like something hitting something metal (like the parking brake line) and not an actual loose suspension component. if it doesn't work, ill wait until my 5000 mile service.

 

I can agree, the bump/thump noise from the rear suspension is more than i am used to with german brands.

 

I can agree, the lack of check engine lights and electrical problems is more than I am used to with German brands.

 

See this thread, particularly post number 4.

https://www.clublexus.com/forums/is-...4-is-350f.html

 

Really? Any thumps I hear are to be expected for a car with a firm/responsive ride. Most of the car mags praise this car for ride quality. This car is practically silent compared to my previous E90 335i. That car had the sport package and combined with run-flat tires, the ride was very harsh and loud. Every little crack in the road was felt and heard in the car. Manhole covers would bang pretty loud and if you ever hit a legitimate pothole, the impact was so harsh and metallic, it sounded like a gunshot.

Google for BMW 335i ride quality and there are countless threads about how bad it is. In contrast, Google for IS350 ride quality and hardly anything pops up.

Keep in mind, this was my experience with the sport package. I have driven several BMWs without the sport package, as well as Audi's A4, S4 and RS4. All those cars rode nice and firm, with any bump noise inline with the IS350.

I test drove a TL SH-AWD a few years back and that thumped pretty loudly from the rear - much more so than the IS350.

I think part of the reason for any rear thumping noise may have to do with the large speaker in the rear shelf and just the total volume of air back there. The trunk can act a bit like a speaker box in that any impact sound can be a bit amplified. I don't sense that the noise is coming from the suspension.

Try running your tires a bit under the recommended 36 psi. Maybe go with 33 or 34 psi. This will smooth the ride out and decrease any bump noise, however the handling will be less responsive.

 

Also, I see that you live in FL. Your roads should be pretty much smooth as glass down there. At least they were when I used to live in FL. Be glad you don't live in the North East. Our roads look like Baghdad, especially in the big cities.

 

roads aren't always smooth, but the suspension noise in the back is there, especially compared to how much quieter the front is (asixe from the clank with the windows down). My 335i had th sport suspension, but it came with ZP PS2's and my M3 came witg PS2's and they seemed less boomu over bumps to me.

 

Try dropping the psi in the rears a bit - that might help.

 

Can try (they are right at 36psi though).


also whoever came up with that parking brake solution is a genius, worked like a charm when I left work today; guess mine didn't need that much time to "tighten" up the slack.

 

Yes my pleasure ..!!!

https://www.clublexus.com/forums/is-...4-is-350f.html


Joe Z