Garber

1991 ka24de-t

just swapped a new motor in.

white bunny clutch setup ( d21 flywheel, 300zx clutch)

got everything together and the car runs good. it is just making a very bad sound.

when starting and shutting off the car, you can hear a clunk clunk clunk. it defeinitely is related to the motor shifting back and forth.

once the car is started it sounds normal at idle.

while revving the car up, it doesnt make the sound. as soon as the rpms stop climbing and you let them hold steady (at any rpm over 2500) it starts making this loud vibration grinding type of a sound (i thought grinding before, im leaning towards vibration now). it doesnt matter if the car is in gear, nuetral, clutch in or out, its the same sound. it gets louder as rpms increase.

when the rpms drop, the sound is there until it drops to idle and then it goes away.

it sounds like it is coming right from the flywheel area (the back of the motor) but its hard to tell because it is so loud.

at first i figured it was the d21 flywheel grinding the dust sheild on the tranny, so i pulled the tranny off and cut the parts of the dust sheild off that it was rubbing. with the tranny off i started the car with just the flywheel on and no dustsheild. it made the sound a very small amount the first time my rpms dropped and then it did not make the sound again. i installed the dustsheild and the clutch and tried it again. no sound. then i installed the transmission thinking i fixed the problem. THE SOUND IS BACK! the exact same as before.


i think whatever the problem is, it is related to the motor shifting. when accelerating (revving) the engine, it shifts to the side and there is no sound. When held steady at high rpms it shifts to center and the sound starts. On decel (rpms dropping)it also shifts to the left side and the sound is there until it hits idle and the engine shifts back to center.

the low rpms starting it and shutting it off cause the motor to rock back and forth which is when you hear the clunking.

i found a couple threads of people with similar problems but none of them updated with results....

soooo what is it and where is it coming from?!? any ideas?



going to get some videos soon

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Garber

this is with fuel and spark not hooked up to hear the clunking:

YouTube - ‪DSCN0204.AVI‬‏

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Garber

well i figured out the problem lol. the flywheel bolts were not tight enough so the flywheel was vibrating back and forth in the bolt holes. now they are elongated by about .5mm

should i get a new flywheel or will i be ok if i just crank the bolts down tight?

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camaro379ss

Tighten the bolts to spec and see if it will work. You got nothing to lose at this point. The worst that will happen is get a new flywheel like you are asking.

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1991 Nissan B13 Sentra sr20det 300whp/1991 Nissan S13 240sx sr20det ~260whp

Garber

brand new flywheel from advanced it $40 so im just getting it. i dont feel like taking the trans out a 3rd time lol

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curbhuggerrps13

i agree...i put a new clutch in on the s14 and an hour od driving later the main output shaft grenades itself....

didderson

IIRC you have to torque those bolts over 100 ft lbs man! Don't forget to check the fsm!
It helps to use a clutch plate bolt hole and bolt a chain to the flywheel, then bolt the same chain to the engine block to torque the flywheel.

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Garber

yes replaced the flywheel, torqued the bolts to 112ftlbs and all is well now.

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