vibration at 1500 rpm

**anniescamaross** · 10-02-2006, 08:33 PM

I have an '02 camaro ss that has a strange vibration at 1500 rpm.It does this at road speed or in park or up on jack stands in gear.It has 44k miles.Anyone have any ideas or have you experienced anything like this? Engine balance problem? Torque converter out of balance? Thanks

**Wesman** · 10-02-2006, 08:56 PM

Originally Posted by anniescamaross

I have an '02 camaro ss that has a strange vibration at 1500 rpm.It does this at road speed or in park or up on jack stands in gear.It has 44k miles.Anyone have any ideas or have you experienced anything like this? Engine balance problem? Torque converter out of balance? Thanks

Since its only at 1500RPM, sounds like either the torque converter or flywheel (flexplate) are out of balance.

Where exactly do you feel the vibration?? Is it in the shifter or the whole car??

**prafopi** · 10-02-2006, 09:00 PM

This could be attributed to detonation issues. Also to be sure, inspect your vacuum lines as it may have been knocked loose or there's a wire connection that came loose.

**anniescamaross** · 10-02-2006, 09:17 PM

It is the strongest in the console area but you can also feel it on the gas pedal. Vibration comes in at 1400rpm,is strongest at 1500 and goes away by 1700rpm.Notice some vibration in the middle of the dash as well.

**808ws6** · 11-09-2006, 11:41 PM

Originally Posted by anniescamaross

It is the strongest in the console area but you can also feel it on the gas pedal. Vibration comes in at 1400rpm,is strongest at 1500 and goes away by 1700rpm.Notice some vibration in the middle of the dash as well.

I experience the same exact vibration you have in my '98 WS6 T/A M6.
It's not driveline cause when I clutch in or neutral, the vibration is still there and with the car standing still.

It starts at about 1400 and gets worse by 1500 rpm then goes away at about 1700 rpm.
The steering wheel shudders as well as the shifter.
Do you have any mods as well?
My car has SLP LT's, gutted cats and stock exhaust. Engine is stock.

ANyone have any ideas? Is it from the headers? Needs tuning?

Was thinking posisbly from the balancer? Are LS1 balancers known commonly for failing?

Thanks!

**bigrondownhiller** · 11-10-2006, 09:46 AM

check for a bad tranny mt. all you have to do is jack the car and push up on the tailshaft. if it moves easily problem found.

**02WS6dream** · 11-10-2006, 01:47 PM

i have this same vibration...spent lots of time and money chasing it...poly trans mount, rebuilt trans w/new torque converter (for more reasons than vibration...), new driveshaft, new tires, and numerous tire balances...and its still there! Actually got worse after the poly mount. So i've just accepted it as 'normal' and now it doesn't really bother me...

**anniescamaross** · 11-10-2006, 02:02 PM

Had a conversation with one of the local LS1 specialty shops and they said they see alot of balancers slip the outer ring and cause some balance problems but also exhaust resonance transferring to the exhaust mount that attaches to the tailshaft of the tranny.Just a few days later the SES light came on with a PO420 code and since it was emmissions related the dealer put on new cats under warranty.Vibration is hardly noticeable now or maybe it just seems that way.Makes a little more sense than a balancer problem unless you've got a front crank seal or something that dissolved the rubber dampener between the rings.Still looking for answers.

**808ws6** · 11-12-2006, 10:43 AM

Thanks for the suggestions and updates everyone!

Yesterday I set the car on hackstands and jacked the trans tailshaft. It move slightly up (from the pressure) but the mount is not visually broken. when you say broken mount, do you really see a torn trans mount or a sagged trans mount?

Interesting note on the exhaust resonance. When I was underneath looking at the trans mount, I noticed the exhaust hanger bracket there as well.
My hunch is also the the exhaut resonating through that bracket.
I am going to try and fiddle with it to see if it improves.

That would explain why after the dealer replaced your cats if seems to have improved. It would have been touched/disturbed just enough to reduce the resonance.
I've hear of the balance outer ring slipping but I am sure the vibration would be at all sorts of rpm speeds. I also indexed mine and checked for slippage, none seen yet.

Thanks for the help!

**YoMommasTA** · 11-12-2006, 01:03 PM

Originally Posted by anniescamaross

I have an '02 camaro ss that has a strange vibration at 1500 rpm.It does this at road speed or in park or up on jack stands in gear.It has 44k miles.Anyone have any ideas or have you experienced anything like this? Engine balance problem? Torque converter out of balance? Thanks

in park says it all,converter or engine balance,could even be a cracked flex plate.One thing you could try is to unbolt the converter and start it up see if the vibration is gone.If it is try bolting the converter bk on in a diff position on the flex plate OR replace the converter. Good luck.

**anniescamaross** · 11-12-2006, 02:30 PM

Tried unbolting the torque converter and running it and the vibes are still there. took all the drive belts off and ran it for a few seconds,same thing.Strange thing is it seems to come and go,thought it was gone after the cats were replaced but as i said it comes and goes.Can't imagine the assembly line letting it go with a crank balance issue but haven't seen a crank just go out of balance after a few thousand miles much less vibrate intermitently.due to the tranny bell housing design I can't see if the flywheel is cracked without pulling the trans but I would assume if it were cracked I would hear some noise as well.Maybe I'll pull the tranny next if no one else comes up with something better.

**YoMommasTA** · 11-12-2006, 06:39 PM

ok so we know its in the engine rotating assembly OR a miss fire. are you the 1st owner?Next thing i would do is check the crank shaft end play.Too much end play will cause a vibration to setup at times.

**anniescamaross** · 11-12-2006, 07:02 PM

I'm the original owner and it has had a pretty easy life.The only mods are a cat back 3'' Flowmaster setup.Seems like the ECM would pick up a cylinder misfire and throw a code especially as frequent as this one.Checked end play at the front of the crank and it is minimal if any at all. Noticed today that the vibes are more noticeable on a cold start than at full operating temp.This is my second LS1,the first was a'98 Formula,auto and don't remember any probs with it.Hate to just ignore it for fear that it will get worse and grenade something.Tried some GM Techlines and they weren't much help at all.