I hear a metallic vibrating/grinding/chatter noise on the passenger side when I accelerate. I only hear it when the clutch is engaged and engine is under load. I hear it particularly strong when accelerating in a right turn but it practically goes away when I accelerate left.

I took it to two shops. The first thought it might be the transmission. The second suspected an intermediate shaft bearing or part of the belt system.

I did a little searching and learned that the right motor mount commonly fails and can cause a similar (same?) noise.

Based on the pictures, can you tell if this mount is defective or not?


  • Brown stuff - hydraulic fluid from the mount or just coolant spill?
  • I easily pressed the center bulge all the way in. No resistance until it touched something hard in the middle.
  • The forward and rear legs of the "floating" portion of the mount are actually resting on the metal below. Is this a giveaway - or normal?

Motor mount side away from engine Motor mount side near engine

Vehicle is 2006 Mazda 3 S 2.3L

Edit 1

It looks like you are all right. I jacked up the engine today and the rubber of the mount pulled right off the metal it was attached to. You can see a big crack in it too. To be sure the mount was in fact the cause of the noise, I stuffed some rubber from an old pair of shoes between the floating part of the mount and the mount frame. Noise gone! Time to order a new motor mount.enter image description here

Edit 2

I bought a new mount off Amazon for $31 and had it installed. Purrs like a kitten now!


3 Answers 3


Whoever said that these mounts commonly fail is entirely correct.

These mounts are oil filled. The brown stuff on top is likely not hydraulic fluid. When the mounts fail they split along the bottom side and the fluid is lost from the bottom. This prevents the fluid from ending up on top. The absolutely best way to tell if the mount has failed is to unbolt it and take it out. If the two half flop around freely or even fall apart then the mount is definitely bad.

You can try jacking up the engine slightly with a jack and block of wood and look at the underside of the mount with a mirror. If you see a jagged gap appear in the rubber then the mount is bad. This is harder to see because there is so little space.

In a brand new mount the two halves are connected together with rubber. That rubber allows them to articulate around but not to separate.

  • "these mounts commonly fail" It's a rubber part on a 10 year old vehicle. I would say that is an extremely probable point for failure.
    – justinm410
    Commented Sep 9, 2016 at 19:00
  • 1
    @justinm410 Those mounts were failing still under warranty, if that says anything.
    – vini_i
    Commented Sep 9, 2016 at 19:03

The forward and rear legs of the "floating" portion of the mount are actually resting on the metal below. Is this a giveaway - or normal?

I don't know about your specific car but what I recall is that engine mounts often use a synthetic-rubber coupling to keep the metal parts separate. It is the rubber that prevents some engine vibration being transmitted into the chassis.

If there is metal on metal contact it suggests to me that a synthetic-rubber mounting may have disintegrated.


Replace it before attempting any expensive repairs. The other items named are pretty uncommon for failure IMO, sounds like they were grasping at straws- especially given that they didn't notice your busted motor mount while looking at it.

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