4 weeks ago my SS developed a vibration...since then I've replaced my underdrive pulley and flywheel (both needed replacing) and i still have this vibration. so externally there can't be anything causing this vibration..


This vibration occurs throughout the whole rpm range, both as the revs up and down. Under load is when you really get this harsh vibration ( but still present at in neutural), it causes the shifter to rattle , its that bad, not smooth at all. But the engine isn't breaking up, still seems to pull fairly good, and idles fine. Hasn' thrown any codes.

Any idea from you guys whats happening here?

Could this be electronic?

I'm lost and frustrated.

 

Did you do the clutch and pressure plate or just the fly wheel?

 

Y-pipe?

 

Yes I did both

 

How could this be my problem...(I really mean it).

Has anyone had anything similar?

 

yea i know its not an ls1 but on my lt1 i use to have, the y pipe took about 100 miles to get to where it wanted on the car. it vibrated and rattled the whole damn car.

 

Check your engine and transmission mounts. Make sure none of them are broken.

 

have u recently done any exhaust work? if so, I can understand the rattling for awhile, but if not..then no. I would agree with 5.3LJimmy, check your mounts..

 

I checked the mounts and they are fine...but i forgot to mention that the car doesn't sound right...sounds like its muffled...being helled back kinda off., but seems to still pull fine, maybe just a slight hesitation just when you punch it, but idles like it all always did.

 

Could this be a coil pack breakin down, or something with the fuel system?

 

Are you running catalytic converters? Unplug your MAF and drive it, see if the problem goes away.

 

No cats.

Has anyone had anything close to this problem

 

if its a manual then you probably put the harmonic balancer on incorrectly. it can be put on croked and cause and imbalance.

 

Did you under tighten or forget to tighten the transmission brace mount under the shifter?

 

It's fine..had the problem before i installed the the new balancer.

 

The brace is also fine.

 

Anyone have any other ideas?

 

Did you take the motor mounts out to inspect? If not thats compress rubber in metal it will hide cracks. Also did u replace the tranny mount? if so did u aline the bolts any. And how about the drive shaft is there excessive play in it? Simply just twist with your hand with the e brake up it should not move at all.

 

when my buddy's ls1 had that problem it was the u joints at about 100k on it. My buddies lt1 did that and one of his tires came unbalanced.

 

I've seen broken valve springs cause shaky engines.