flywheel problem?

[ayjay]

ever since i have owned my 1990 240sx, there has been a strange sound when idling, and during acceleration in 1st and 2nd gear.

It sounds like a galloping horse or sumpin like that, and I have been able to pinpoint it to the transmission/clutch/flywheel, because if i'm sitting at idle in neutral and i push the clutch in, the sound goes away. So in other words i only hear this sound when the clutch is engaged. something to do with flywheel?

also, just recently i have been noticing hesitation around 2500-3000 rpm, and some power loss. so i replaced the distributor cap/rotor, thinking that it would solve the problem. well the hesitation went away, but it still lacks high end power from 3500-6000. i can go just as fast as if i bring each gear up to 3500 then when i bring them up to 6000. normally in 2nd gear when i hit about 3700+ i got some pretty good pull, but now it pulls just as hard at 3000 as it does at 4500. the rpm's are increasing accordingly which leaves me to believe that the clutch is fine and is not slipping. flywheel again? maybe coil?

any suggestions would be great!

[Und3rprshUr]

Whats makes you think flywheel ??

flywheel is turned by motor if there is no power either motor is making no power or clutch is slipping.. flywheel arent replaced freq. like dist. caps..

[NISTECH]

i would guess pilot bushing for the noise first to second when clutch is in. power loss is unrelated. hows your fuel pressure at the rail?

[p00t]

sounds like the throwout bearing

how many miles are on the car? has the clutch been replaced? was the throwout bearing replaced with the clutch?

the pressure plate normally still makes slight contact with the throwout bearing even when you dont have the clutch pressed down, if the bearing goes it will become very rough and noisy, and when you push in on the pedal its putting pressure on the bearing and shutting up those rattling peices. does it feel alittle rough when engaging/disengaging the clutch?

if you decide to drop the transmission go right for the throwout bearing and turn it by hand, if its hard to turn the part, rough, or lose and rattlely, the bearing is your problem.

[float_6969]

I'm with poot. I had a throwout bearing go out in this car and it sounded awful. Unfortunatly I drove it till it shelled the bearing out of it and screwed up my clutch. I'd get it fixed asap. Some shops don't replace it when they replace the clutch. I know the clutch had be replaced at some point, but it was the original Nissan throwout bearing. Had almost 200,000 miles on it. Poor thing...

[Holisticbeatz]

But a throwout bearing wouldn't make a "galloping horse" sound when worn out. It's more like a rattling of BB's inside a rusty can.

Questions: How many miles do you have on your motor and when was the last time the clutch has been changed?

[float_6969]

Mine actually made a high pitched squeal when it first started. And the "galloping horse" description isn't too good. I'd prob have to hear it for myself to be sure, but it HAS to be something in the drive train.

[ayjay]

sorry guys, i have been too busy to check this thread since i posted it... thanks for all your help/suggestions!

i think it's most likely the throwout bearing... my car has an amazing 290 000 km's on it (180K miles) and as far as i know there is a rebuilt engine in it with 120k kms on it. the clutch has most likely been replaced, but i don't know about the throwout bearing.

do you guys know how much it would cost to replace the throwout bearing? i replaced the timing chain myself, so you think i am worthy enough to replace this bearing? :rolleyes

the thing is, it doesn't feel rough when engaging/disengaging the clutch, and launching the car from a stop is still quite smooth... it's just the damn noise that it makes.

and YES, the GALLOPING HORSE noise is exactly what it sounds like... it's not a rattling sound, it's definately a horseshoe on a road sound :pface

[Touchdown038]

Is your noise very faint / hardly noticeable? And does it make it when you're standing still in neutral with the clutch engaged? If so, I have the same problem, and I need some help with it.

[float_6969]

Well you have me stumped. I still think it's the throwout bearing, but I don't know how it would make that noise. Have you checked to make sure that nothing is wraped around your driveshaft? try putting the car up ON JACKSTANDS, start it and put it in gear and see if you can track down where it's coming from underneath the car. As for how hard to change the bearing is, not really. Getting the transmission off is the hardest part. I hate doing that on this car. Getting it to line back up is even worse. Try that and see how it goes.

[drjohn]

The noise you are hearing is in the trans and probably is the rear counter shaft bearing.When the clutch pedal is pushed down the release bearing is ingaged and the input shaft is spinning in the pilot bushing.This takes the pilot bushing and release bearing out of the diag.because both are rotating.With the clutch out in neutral almost everything turns in the trans except the output shaft.