Car vibrates going over bumps

[last_shot]

For a while now I've been noticing that the front of my car vibrates everytime it goes over bumps on the road. Do I need new shocks?

[last_shot]

Sorry, wrong forum. Mods can you please move this to the Problems section.

[whiteomega]

what kind of vibrations? does it shudder, or rattle, or do something else?

[last_shot]

It shudders. I've got an 05 Sport GT if it matters.

[Donutz]

How does it shudder? Do you get feedback through the steering wheel, a pedal, the cabin, etc?

[last_shot]

It's felt throughout the cabin.

[whiteomega]

well, it's probably not your shocks, as generally when your shocks go, the car starts to bounce on bumps, and won't stop (the spring is basically compressing and rebounding continuously since your shocks aren't doing anything to dampen the movement).

we still need more detail to figure out what's going on. does this happen at slow speed, at high speed, over speed bumps, etc? are you turning when it's happening?

[last_shot]

It happens when going over hard bumps at any speed. Bumps like streetcar tracks and pot holes.

[-RJ3-]

HAve you gotten an alignment ever since?

Possibly you need one.

[last_shot]

I had an alignment done last year and it still seems fine now. Car drives straight...even tire wear. The front end was inspected when I put my summer tires on and it was fine. Ball joints, tie rods, wheel bearings are all good.

[last_shot]

Anyone have any opinions on this?

[Donutz]

It's really hard to say. The symptoms are somewhat vague. Is your car modded at all?

[last_shot]

It's really hard to say. The symptoms are somewhat vague. Is your car modded at all?

Yeah, I know it's kind of hard to explain. My car's bone stock.

[Donutz]

Manual or auto?

[Nick]

could be something as simple as loose nuts, double check them

[Halogen]

Its because your still accelerating (ie: gas pedal) while going over bumps in the road. The wheels will over turn for that slight second it takes the wheels to drop an contact the road this will cause shudders in the front end. I noticed this right away and have adjusted my driving habits.

I drive 5speed, so I time my shifting around road conditions, and never hit the gas while going over rough sections of roads, like train tracks and other obstacles. I get far less drive shudder now. Try coasting over rough sections and tell me if you feel any difference.

Could also be that the suspension in the 3 is so damn responsive or you have something worn, like the engine mount, I've read these sometimes go early in the 3 (?)

[last_shot]

My 3's an automatic. It happens even when I'm just coasting over bumps. It's getting really annoying though living downtown with all the streetcar tracks around and the crappy roads. I guess I'll just have to bring it in to the dealership and have them check it out. Thanks anyways though guys. I'll post the cause of it when I find out.

[TokyoKiller]

My 3's an automatic. It happens even when I'm just coasting over bumps. It's getting really annoying though living downtown with all the streetcar tracks around and the crappy roads. I guess I'll just have to bring it in to the dealership and have them check it out. Thanks anyways though guys. I'll post the cause of it when I find out.

I have the same problem...my car also vibrates on the highway. I've gotten an alignment and balancing done and it still does the vibrations on bumps and at higher speeds.

[last_shot]

Could also be that the suspension in the 3 is so damn responsive or you have something worn, like the engine mount, I've read these sometimes go early in the 3 (?)

I brought the car into the dealership today and had the tech road test it with me. His diagnosis was the engine mount so they're going to fix it under warranty. Hopefully the problem will be gone.

[wtom]

Check your engine mounts. One of them may have broke/leaked. The passenger-side engine mount is notorious ... ok maybe not notorious but known to go prematurely.

[last_shot]

Check your engine mounts. One of them may have broke/leaked. The passenger-side engine mount is notorious ... ok maybe not notorious but known to go prematurely.

Yeah, that was the one they replaced. They also fixed my tranny problem too where it jerked from 1st to 2nd on cold starts.
I'll be bringing it back Monday to have them fix the rust issue around the rear wheel well as well. I'm glad this is all done under warranty.
Thanks for the help guys!

[pbarnett221]

I have an '07 Sport GT, and I am having the same problem. Back drivers side wheel...going over bumps means a jaw shattering shudder. Going thru turns and hitting a manhole will tend to have the back end want to swing out. I brought into MAZDA today...they said...the SHOCK is GONE on that side...meaning all the fluid has leaked out!!! They are gonna replace it under warranty (you better believe it they will!).
I'm not impressed though in that the car is only 2.5 years old with not mods done to the car mechanically except...18" wheels.

[TheMAN]

18" wheels put more load on the suspension dude

[johnk]

What do you mean by engine mounts may have leaked?

[ST3ALTH]

18" wheels put more load on the suspension dude

Huh? how does the size of the rim put a load on the suspension? the car is the load on the suspension, not the rims. Maybe if i put the rims on my roof! lol

[TheMAN]

holy thread bump!
bigger/heavier wheels changes the suspension load/performance... it's called unsprung weight, look it up!

[ST3ALTH]

ok well i just find it hard to believe that the bigger the rim the more stress or damage you could cause to your suspension.

Unsprung weight includes the mass of components such as the wheel axles, wheel bearings, wheel hubs, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. If the vehicle's brakes are mounted outboard (i.e., within the wheel), their weight is also part of the unsprung weight.

The unsprung weight of a wheel controls a trade-off between a wheel's bump-following ability and its vibration isolation. Bumps and surface imperfections in the road cause tire compression—which induces a force on the unsprung weight. The unsprung weight then responds to this force with movement of its own. The amount of movement, for short bumps, is inversely proportional to the weight - a lighter wheel which readily moves in response to road bumps will have more grip and more constant grip when tracking over an imperfect road. For this reason, lighter wheels are sought especially for high-performance applications. In contrast, a heavier wheel which moves less will not absorb as much vibration; the irregularities of the road surface will transfer to the cabin through the geometry of the suspension and hence ride quality and road noise are deteriorated. For longer bumps that the wheels fallow, greater unsprung mass causes more energy to be absorbed by the wheels and makes the ride worse.

Yes in a performance setting, the lighter the wheel the better, but i still have yet to find the size of the rim affecting the suspension!

[prime]

Bigger rims means less tires? Less tires means a rougher ride, thus the connection to more stress on the suspension since the tires are absorbing less vibrations?

Although, bigger rims doesn't necessarily mean heavier.

[TheMAN]

your usual aftermarket rim is heavier, unless you go for those expensive brand name tuner wheels