ok someone help me please ! i have bought a 1992 mx3 ,automatic,, 1.6 ,4 cylinder the trouble is when we start off moving the car sakes and vibrates in the front end very ver badly , then once movin i stops, then when it shifts itself into second it does it very mildly . ?? now i have replace the axle half shafts with BRAND NEW ONES , new rotors and brand new motor mounts ! please some one tell me what i can do to stop this shaking its my daughter first car !! the transmission shifts fine and drives fine brand new tire also ,,help please !!!

email me at lang512@aol.com or here -- if you can call in florida 850-863-1207 ask for tom thanks everone and GOD BLESS YOU ALL ,tom langford

 

Was the car shaking before all this major work was started, or were you trying to do maintenance? The reason I ask is the only thing I could think of is an axle shaft not fully inserted in the transmission completely.

I would jack up the car and support with jackstands and place them under the control arms as to support the weight on the suspension. This way all the suspension geometry is correct as if you were going down the road. Then start the car and put it in drive and observe under the car to inspect if anything is binding.

 

You are describing a vibration such as perhaps the engine is running rough and jerking or does it seem to be more related to wheel movement. You might try putting in D, stepping hard on the brake and then floor throttle for a few seconds and see if that vibration is still there. No that will not hurt anything. It is called powerbraking and is a procedure used to check trans line pressure at stall speed. Just do not hold throttle open for more then 5 seconds or so. I am thinking that perhaps the intake boot between the air cleaner and engine is torn open. Does it do this same thing in reverse?? A somewhat common problem is that the flexible rubber boot will tear open a bit, usually on the back side, and when you go to accelerate the torque created by the engine rotates the engine slightly and opens up this tear resulting in a very lean condition. Give that boot a very careful check over and make sure that it is not damaged at all.