car is shaking at idle and at 120 kph

[reznorx99]

hi my 96 mx3 is shaking bad at idle could this be a engine mount ?
and at 120-130 kph it feels like the shaking is coming from the back side of passenger side. thx for any help

[Inodoro Pereyra]

You'd have to provide more information.
For example:
What's your idle speed (RPM)?
Is it always shaking when idling?
Is your idle stable?
Do you feel a bump when either you hit the throttle on gear, or when you release it when moving?
How old are your shocks?
Are the shocks in good shape?
Do you hear any noise coming from the rear of the car, and if you do, when does it happen, and what kind of noise is it?

Welcome to the forum.

[reznorx99]

thx my idle speed is 1000 rpm and it is always shaking at idle
i don't feel any bump and my shocks are in good shape
i don't hear a any noise just shaking at the back end p/s

[Inodoro Pereyra]

Hmmm, I would first check/replace my spark plugs, wires and distributor cap. Your idle speed is a little high, but that should make the engine vibrate less, not more.
Also, look for oil inside the spark plug tubes. If there's oil, you'll have to replace the valve cover gasket. Make sure you buy a set that contains the spark plug tube seals. Also, it'd be a good idea to put a good quality injector cleaner in your gas tank, and see if it solves the problem.
As per the rear shake, the way I see it it could be one of 3 things: either you lost the balancing weights on your rear wheel (take it to a tire shop and re-balance them), or one or more of your suspension bushings is worn/broken, or something in your rear suspension is loose.

[reznorx99]

i got new plugs and wires and distributor cap and there's no oil
i will look at the wheel and suspension tomorrow and thx for your help

[Inodoro Pereyra]

You're welcome. Another thing you can do, being that your car is OBD II, is take to an auto part store and run a diagnostic, to see if you're having any problem the computer can detect.
Other than that, I don't know. If the engine mounts were bad, you'd feel a thump when you change the throttle input to the engine, especially when in gear.

[Thassodar]

For the shaking at higher speeds, I suggest getting your tires balanced. Mine are currently unbalanced in the rear so at 70 mph+ my car shakes like crazy.

[Ryan]

Mazda's motor mounts were poorly designed in this era of vehicle. They all shake at lower RPM's, moreso as you get lower, to the 700 area where its supposed to sit. The redesign of the motormounts is the only reason the newer cars don't shake so bad at idle. I wouldn't worry about it.

Unless of course you're misfiring, that would also cause some bad shaking.

The high speed shake is most likely tire balance.

[reznorx99]

thx for all you help guys