need help w/ diagnosis BADLY, gotta little prob. w/ the celi. Options

[Mynzeyes]

ok first. i need some help figurin out what's up w/ the celi...

here's all the prelim. info:

94 celica st 7afe automatic hatch. whee.
i have a slight vibration/shake under 1/2+ throttle in the ranges of about 35-80mph and 2500+rpm. now, the shaking stops when i left off the gas, and is more severe under harder acceleration. the vibrating and all is in no way affected by braking or turning, only under acceleration. though it is more concentrated in the ranges mentioned, it CAN be felt VERY slightly before and after that range (though this may be my imagination and pessimism kicking in?). also, rpms stay constant, and do not bounce or anything, and i have a steady idle.

my own diagnosis:
i have recently replaced my axles, due to another problem i was having. i have ruled out a balance/alignment problem, due to the lack of shaking while coasting at speeds mentioned. though i thought possibly it may be a mild balance prob.

i have also ruled out a major engine/fuel/etc problem, because the RPMs do not bounce at all, at idle, while shaking, or while coasting.

another idea is that it may be engine mounts, but i was informed by a friend that the shaking w/ those tends to cease around 1500-2000rpms.

a fellow at a local tranny shop said he felt somethin in the rear w/ the shock/strut, but i asked him how that would make it feel like the front shakes under acceleration, so my next thought would be that maybe the front are gone too, but i was wondering if that would affect ONLY acceleration, i figured that would cause it to shake and ride like crap 24/7, but that is not the case.

i've had wheel bearings/hubs go out before. and you could always steer into/out of the shaking, and that also comes w/ a nasty noise, my prob. seems to have no noise, other than the sound of the dash shaking...um...and i've lifted the car up, and tried the shade-tree mechanics test of bearings, and there is no play at all in the wheels.

my solutions thus far, and in the near future:
new axles.
rotation/balance of tires.
spark plugs and fuel inj. cleaner.
possibly motor mounts.

bleh, someone help please. other than in the ranges and circumstances described, the car rides very smooth and well.
i feel i have a pretty indepth description of what's going on, and if anyone needs anymore info to make a diagnosis, ask away, and i'll do a test drive again and answer the question.
thank you all in advance,
-John-

[Mynzeyes]

ok really. we need some gearheads here at 6gc.net. evidently no one knows a whole lot other than aesthetics crap..bleh.
-John-

[boosted_K2]

the ST engine mounts are rather crap, very loose to begin with... so unless your friend check your mounts himself i wouldnt completely rule that out.

[Mynzeyes]

QUOTE (K2_Celica @ Dec 4 2002, 03:56 PM)

the ST engine mounts are rather crap, very loose to begin with... so unless your friend check your mounts himself i wouldnt completely rule that out.

i talked to the transmission shop guy here. um...it's somethin in teh driver's axle, w/ the bearing link/cup that goes into the tranny. the vibration while sitting still is the tranny mounts..any time you have a vibration under acceleration in a certain mph/rpm range, and it goes away if you let off the gas, you can be pretty sure it's the axle.. i was just blind to that because i just did some axle work. but that's life, hehe..and btw, motor mounts would shake no matter what, in gear or in neutral, but they would stop after 3k rpms about.. thanks tho K2, i just found all this info out today..and the newest vibration is a pesky warped rotor, but that's solved w/ a simple turning at NAPA..wheeee.
-John-

[nandincelica]

its very possible with exhaust leak or circulation check your egr valve !!!!!!!!!!!!!!

[Batman722]

your advice may of been relevent 6 years ago.
this is a post from 2002 and John has since sold his celica (I think) and has a Sentra now.

[95celgt]

well yea this post is from 2002, but I am VERY glad he popped it up because this is exactly what i was asking in a thread and no one knew the answer, so was it the axle or tranny???

[Batman722]

axle IMO

[Taskbot]

holy revived thread