Serious vibration issue but have changed many parts

[kloog]

My car is a 1991 protege with the 1.8 dohc
I have a serious vibration issue in drive/neutral/park that occurs when rpms are below 900
I have so far changed all 4 mounts, radiator mounts, timing belt, checked timing(it was perfect) and a complete tune-up

someone suggested to me the harmonic balancer but the crankshaft pulley (which is where my manual says it's located) is just a solid pulley with two sets of grooves for both belts. does anyone have any suggestions on how to find the harmonic balancer or check it.
Thanks

[Jho]

The harmonic balancer IS your crank shaft pulley. It is supposed to be balanced. If it is not, it will cause a serious vibration.

[kloog]

how would I check if it is balanced

[Jho]

Well if it is the original, and this problem wasn't always there, then I would say that the harmonic balancer is not the cause. They come balanced from the factory.

[wheresthericego]

Make sure all the mounts are torqued properly, or at least tight

[Jho]

Make sure all the mounts are torqued properly, or at least tight

Or are the right mounts to begin with and are installed properly.

And make sure that the lower tranny brace is tight and that the bushings aren't too worn and still exist.

[kloog]

Well , i've acutally removed and installed the mounts several times to check for issues. each time the vibration is the same. I do tighten them properly but you would think there would be some varitaion between installs if under/over tightening was the problem.

[Jho]

Over tightening wouldn't cause a vibration, it wouldn't really cause any negative effects, as long as you didn't break anything.

Under tightening, sure, if they were loose, or loose enough that the bolts would rattle loose, that would cause all sorts of vibration.

[kloog]

Well they are all new mounts, and even after changing each one at a time over the past year the vibration level never changed.

[Jho]

What kind of mounts are they?

[kloog]

anchor for the two on the crossmember. I don't remember the brand of the one under the battery and the one near the timing belt cover

[jacobrussell]

heres one you probably didnt think of

change the jack shaft/ prop shaft ( the axle that mounts to the motor)

[kloog]

would the drive shaft cause vibration at idle though?. The car drives very smooth

[jacobrussell]

have you looked at the shifter bushings?

[kloog]

The vibration is most prominent in the wheel and frame and only during idle the shifter is smooth