The Symptoms...
 

Patient is a white 15 y/o GTU complaining of vibration upon acceleration in the 3-5th gears. Pt. has had an oil change, new bushings, fuel filter repl., O2 sensor repl., and of course, a fuel system cleaning within the past 6 mos (not that any of this may be relevant).

Ok no more shenanigans. I want to know what you guys think before i take it to the mechanic. My bro thinks it needs a new flywheel... but he's not very bright.

Please help me make a diagnosis!

Peace unto you all.

ps. Something feels loose..

Maybe a little more information would be useful. Is it only in those gears or just pronounced in those gears? What speeds is it happening at? Anything you can provide will help us to diagnose.

Offhand I would say it is an unbalancesd driveshaft just because that is a common occurance in our older cars. Another thing I would suggest is a sticking caliper. I had this problem a little while ago. It vibrated around 60-70, went away and came back around 80 or so. Replaced front calipers and rides like a dream now. It was especially bad after I had braked several times or hard.

pronounced upon acceleration (in 3-5th gears), car glides to the right when i brake sharply sometimes, i hear something rattling (or loose) during acceleration... the car just doesn't feel tight. It runs fine though.

Just based upon you saying it veers to the right when you brake sharply, I would say a sticking caliper on the right or the left is not engaging the rotor at all.

As for the rattling where does the noise seem to come from? Is it coming from the tranmission area, farther back (driveshaft), or in the front? Also, when you are accelerating, can you feel the vibration in the shifter?

thank you acidshock, ill take it for a spin and see if i can get a better description on what's going on. i appreciate your help.

-c