my festiva STILL shakes!

[evanna]

i've posted on this site awhile a go (maybe a year or so) about a serious shake in my car. i have a 92 ford festiva GL, and since my daddy and i got it about two years ago....we've replaced pretty much all suspension parts, replaced the old motor mounts with the ones off of festivamotorsport.com (excluding the rear motor mount...it was replaced with a used one thats in better condition) and when the transmisson died we replaced it (with one out of a junkyard...which is prolly just as bad). we also rebuilt the head because when we got it, the car was running on only three cylinders.

the shake starts around 45-55 mph and just gets worse from there....the door frames start to flap around and you feel it vibrating through the steering wheel. it also vibrates when idling in drive (BUT when raising the rpms the shaking stops, so the idling could be incorrect)...but of course, not in neutral (and this is with the junkyard transmission). so where do i begin? after replacing the motor mounts, we put the car up on stands to see if the engine shake....but we know its not the engine b/c if it was it would also vibrate in neutral. the only thing we havent checked for is to see if the bearings and the rotors are good.

ALSO, when we took it to get aligned...the mechanic said that he couldnt adjust either the caster/camber b/c there was a lack of room. could it be the frame? i suggested to my dad that we put sway bars (rear and front), tie bar, underbody braces (cant find any though)...thats about all i can think of right now, any ideas?

evanna

[b3 madness]

Out of balance on the tires? Bent rim? Out of round tire? The last one I listed, out of round tire, is one that I recently experienced with a new tire purchase. Had to return the tire for another new one because the shake was so bad.

The shake that you describe while at idle in drive with an automatic transmission is somewhat normal. If it really bothers you then you can bump up the idle a little. You also mentioned swaybars. The Festiva front end has an integrated sway bar and I do not believe that this is the root of your problem.

[Gforcefd]

Here is one, it was in a wreck that you don't know about and the unibody is out of aligment...

[Dave G]

Out of balance on the tires? Bent rim? Out of round tire?

Any of the above coupled with bad tie rod ends?

First thing I'd do is find a shop that will align it for you. If you've replaced a bunch of suspension components and have not have it re-aligned since then, it definately needs it.

[evanna]

Out of balance on the tires? Bent rim? Out of round tire?

Any of the above coupled with bad tie rod ends?

First thing I'd do is find a shop that will align it for you. If you've replaced a bunch of suspension components and have not have it re-aligned since then, it definately needs it.

i've already had it aligned, thats when the guy that aligned my festy said that he couldnt adjust the caster/camber (i dont remember which) any more than he did. we did suspect that there was a wreck...but we have to rule any other possibilities out before we go looking for a bent frame. we havent checked the bearings or the rotors yet.

[miami man]

someone here said measure the distance between the front and rear wheel on each side and see if one side is shorter. someone else can jump in and give more details

[b3 madness]

You should also measure on the diagonal meaning measure from the front driver's side axle to the rear passenger's side axle and then swap sides. Use the same reference points for measuring and compare the two measurements. You should be the same on the measurements if your frame, axle, etc. is not out of wack.

[FestYboy]

the shaking while in drive at idle may still very well be the engine, or combination of engine and flywheel/torque converter. See, when you put the car in drive, two things happen: you put a load on the engine, and the rpms drop (or they should). even if the engine and drivetrain are in perfect balance, any differance in injector pulse width, valve lift/timing, or spark timing can cause a variation in power delivery and/or potency. these differances can/will cause vibrations, along with the lower rpms which can induce sympathetic vibrations and cause the car to shake. with symapthetic vibrations, the energy needed to start them can be miniscule, but since they just happen to be vary close to or even match the natural harmonic of the item that it's shaking, the vibration will naturally amplify itself. given the mass of the car body, this vibration can become quite severe.

now, about your shaking at speed; i'm going to rule out tires right away (though out of balance tires can't help matters). the reason i say this is because tires TYPICALY only cause a vibration in a narrow speed range and then go away (sympathetic vibrations). you state that the vibrations get worse as speed increases. i'm going to assume that the vibrations actually start around 25 mph but they are very subtle and only realy get noticeable at 45+.
first thing we need to rule out is any loose suspention component (tierod ends, ball joints, shock mounts, and trailing arms/sway bar (the sway bar is a dual function unit)). next, you need to inspect your struts/shocks for leaking or the inability to perform their job properly. then move on to your bearings. the last thing to inspect are your rotors (easy part). to do this, find an open stretch of tarmac that is SMOOTH. get to about 30 mph and then LIGHTLY apply your brakes (you may have to do this several times with varying applications of pedal pressure, just make sure once you apply the brakes, you don't change the pressure you've applied) . If you feel a pulsing in your brake pedal AND the steering wheel shakes, you have warped rotors. if you only feel it in the pedal, test again but instead of using the brake pedal to apply the brakes, use the E-brake handle (with thumb on the button so that it doesn't latch). If the handle pulses, you have warped drums. worst case, you have both warped rotors and drums.

Fix all problems found first, then lastly, balance the tires (DO NOT HAVE THEM STATIC BALANCED) Alignment shouldn't have any affect on your shake problem.

finding the problem MUST be done systematicaly or the true cause of the problem may go unfixed.

[25Horseplay]

They make camber/caster bolts that are offset so you can align the front end. I had a similar problem and a new set of rear struts cleared it up.

[evanna]

alright! so i'll check the bearings and the rotors this weekend now and see what happens, i really need to get my festy back on the road so i can start on my mitsu. eclipse. after that i should begin posting within this coming year on my awesome festiva project! i hope i can get to the bottom of this problem by next week! wish me luck and if anybody has anymore suggestions...please post!!