Daniel6718

got my motor rebuilt...installed it...i just fixed the injectors now i have no miss and excellant throttle response...problem is at 3500-4000 and beyond it vibrates BAD! i men im scared to take it over that and my car(other z28) shifts at 7000
the motor was turned 10 on the mains i think and the rods were fine...i have a stock balancer and stock cam ect...stock flywheel but i had it resurfaced while it was out...should i expect its the flywheel? does it have to be zero balanced?
daniel

Daniel6718

anyone had similar problem...?
i only found one thread that semed similar and it cam out to be the flywheel...
ive felt vibrations but i feel like im driving down the bumps in the road at about 15 mph...and im not even moving...the car seems like its goana rattle itself to death

bmwmcars

do you have the tc bolted up properly? i think you could try disconnecting the tc from the motor and pushing it back a little and run the engine as a quick test without the driveline hooked up. that would at least tell you if its engine side or driveline side.

Daniel6718

nope...its s 6 speed...sorry...i said it was resurfaced thouse it was understood

bmwmcars

doh, true enough, i was paying attention to your sig, not your post.

Daniel6718

think its the flywheel? i guess im start pulling the tranny tomaro...i cant believe its causing this bad of a vibration...

Daniel6718

ok well i trie d a few things...i pulled the crank pulley and strated it for a sec reved it and it was better than before then i reinstalled the crank pulley and no at idle it vibrates, its bad at around 2000 on the way to 3 it gets better and from 27-240 or so its pretty smoothe...then above 3500 it gets bad again...any ideas?

1racerdude

The clutch may be doing it. Originally the flywheel had a paint mark on it and the pressure plate is marked too. If ya didn't have the clutch balanced with the internals ya got to line up the marks.
Take the bolts out of the PP and rotate it around one set of holes. Ya may have to do this more than once.

Daniel6718

i thought it only fit one way...isnt there a stud on it where i can only go on one way???

1racerdude

If there is then it's probably not the clutch,but if it was removed for surfacing the ya might want to check it to see.

Daniel6718

im not asking about the clutch....this is with the clutch disengauged...it has to be from the crank poulley to the flywheel...and i think its the flywheel...it was only resurfaced...id really like to exhaust possibilities before i pull tranny and install an auto flywheel and try that...
it doesnt shake at idle...from 1000-2000 it vibs from 2001-3500 it is SMOOTHE...and then above 3500 the car vibs again

1racerdude

The PP is spinning whatever the position of the pedal!!!!!

Daniel6718

yeah but the pressure plate is zero balanced...is remember seeing weights on it when i installed it...

1racerdude

Might be but it wouldn't hurt to check. There are not any weights generally. There may be drill holes.
But it's your engine, check if ya want too cause ya seem to already know the answer and want to put the blame somewhere else.

Daniel6718

so you think i need to turn the flywheel? or the pp?