94 Mirage 1.5L with an Auto. When in gear and the brakes are applied the car shakes pretty good. Worse in Reverse and better once it warms up. No vibration going done the road or in Park. Possible worn mounts?

 

How quick is the vibration when you moving slow?

 

A very little bit at idle. It gets worse when the brakes are applied at a stop

 

WHen you say at idle, is it in gear?

 

Does it shake like the car is about to shut off? or is it he engine mounts?

 

It only shakes when it is in gear. And especially when it's in gear, but stopped. It shakes a little when going really slow. But once you get moving the shake goes away. It doesn't act like it is going to die, but the idle does seem a bit slow. As the car warms up the shake is not as bad, but it is still there.

 

Its has be something with the transmission.......I have not worked much with automatic transmissions. I have a friend that has more experience, I'll explain the problem to him see what he has to say. I would count out the motor mounts, just because even if there good and the motor has a violent shake to it, they only damper it. A bad motor mount would be more like a thump or bang. Have you checked the fluid on your transmission? The car has no performance lose right?

 

No performance loss at all. No slow start or hesitation. All the fluids look good. The shake is at its worse when the engine is cold, brakes applied and it is in reverse. It still shakes in forward gears when cold and brakes applied, but not as bad. The shake completely goes away once the car begins to move above 3 or 4 mph, even if the engine is cold.

 

Have an assistant place the car in gear and get it to start vibrating. From there, use a large prybar and pry slightly on each of the motor mounts to see if it will relieve the vibration. Also, with the vehicle in gear and the brakes depressed completely- try stepping on the throttle just a bit and see how much the engine moves- do this in forward AND reverse. If it rolls quite a bit and/or the noise goes away- I'd suspect one of the front or rear roll stoppers mounts.
Also check your idle speed. If it's idling too low, it will vibrate very bad ESPECIALLY if your valves are out of adjustment. ( The 1.5L are well known for burning exhaust valves do to insufficient valve lash clearance)


Joel, CA

 

Turned out to be the rear motor mount. Thanks for the help