Shaking/vibration during accelerating or idle

[JDBioco]

Hi! I have a Mazda 3 s sedan 2008 automatic. I'm having some shaking/vibration when my car is at 25 km/hr to 35 km/h. When idle at 2200 rpm to 2500 rpm the car shakes/vibrates.

[SonicBoy]

The first generation Mazda 3's were known for poor engine mounts, namely the rear.

Take a look at these components first.

[Kiewan]

+1check the motor mounts. Same thing happened to me when I broke my drivers side mount.

[Flagrum_3]

There's a possibility its a motor mount, but most times if you have vibrations at a 'specific speed range' as the OP points out, it is most likely an out of balance tire.

_3

[crxgsr]

There's a possibility its a motor mount, but most times if you have vibrations at a 'specific speed range' as the OP points out, it is most likely an out of balance tire.

_3

You will probably only feel the "Out of balance tire" from 80 km/h to 120 km/h"
At low speeds it could be a tire belt separation.

But if you just rev the engine while not moving and you get the vibration, it's most likely the mounts.

[Flagrum_3]

You will probably only feel the "Out of balance tire" from 80 km/h to 120 km/h"
At low speeds it could be a tire belt separation.

But if you just rev the engine while not moving and you get the vibration, it's most likely the mounts.

That's not necessarily true, a unbalanced tire is unbalanced. What speed it occurs at depends on several factors. I personally have dealt in the past with tires being out of balance at lower speeds and quite noticeable, but I'll agree it is usually at higher speeds.

To add to your second point; Open the hood have someone view the engine. Engine running, in drive, foot on the brake, rev the engine slightly. If it's the rear mount in most cases, you should notice excessive engine movement.


_3

[JDBioco]

Hi! I tried today to check the transmission mount. How do i know if it is already defective? I've when i rev the car the rubber inside the mount shake a little bit, is it normal?

[Lmmorden]

I have oem motor mounts if your looking.. Msg me

[JDBioco]

Guys! I've already change my transmission mount (OEM) the shaking is now gone at 25 km/hr to 35 km/h but there is still a little bit shaking at 25 km/h when i try to accelerate fast. Do you think it's my rear mount is the other culprit?

[JDBioco]

Hi! I already changed the rear and transmission mount and my m3 is now running smoothly, thanks for the help. But there is still a little bit shaking sometimes when i'm at 20-22 km/h, i can feel that the shaking is from the right front side, could it be also the passenger mount but i already check it no cracks and no spillage of oil and in idle during a stop i can feel the car is shaking. When i check the engine when i rev it i can see the engine is shaking even in park mode and at around 2000-2200 rpm i can feel the vibration in the car. If more than that no vibration anymore.

[JDBioco]

Bad things happen today when i check again the passenger mount. According from the other forum:

"Inspect one of your motor mounts. The easiest one to inspect, is the one that is on the passenger side of the engine bay.

The motor mounts are not solid, they are a rubber bladder with oil interior. When the mount blows, the oil will be easy to spot under the motor mount. Also you can press on the rubber top of the mount, if it feels solid, you are ok, if it feels floppy the fluid has leaked out."

When i press the rubber top of the mount, it burst! the rubber was teared and the oil leak out!!!!!!!!!!!!!!!!! :bang

[MS3_]

People here probably said this but the gen 1 3s and even gen 2s has weak mounts from mazda. Id change all of them if i were you. Passenger, driver and rear and get ur wheels balanced.

[sarujo]

Agreed that the mounts are weak - you can thank Ford for this! I changed my passenger mount on my 2010 gen2 around 85k - top rubber was cracking and was looking to break any time. Just replaced (102k now) the transmission mount on the driver's side after getting strange noises and much louder noises coming from the engine area into the cabin. Oddly the trans mount looked to be ok, but it was not! The trans mount is not fluid filled like the passenger side.

OP - if your passenger mount is over 60 or 70k I would seriously look into replacing the passenger side - but get your tires checked and re-balanced first. ;)


People here probably said this but the gen 1 3s and even gen 2s has weak mounts from mazda. Id change all of them if i were you. Passenger, driver and rear and get ur wheels balanced.