i have a funny vibration...

it vibrates only from about 15-40 (no matter how hard the acceleration) then goes away. it only vibrates when the gas is pressed, either accelerating, or cruising speed, and goes away completely when i let off the gas. it doesnt matter what gear its in, happens in all gears.

from searching i found:

center support bearing-- i do have a strange rattle, but vibration only when gased.
CV-- look fine upon inspection, and no clunks when turning, or anything.
bad motor/trans mounts-- doubtful, and only cause vibration at low speeds?
bad driveshaft-- its smooth at 45 mph all the way to 120.
boost leak-- would this cause a vibration only at low speeds or anytime i go to accelerate? VAG-Com shows no misfires however. i do have a vacuum leak and code for EVAP small leak intermittent...not sure where to look for that.

heres a link to the sound i hear.... http://s466.photobucket.com/albums/r...t=VID00003.flv

i am thinking this may just be the exhaust, cats going bad, but it doesnt do that when i rev in place. and notice the high pitch rattle when i gas it lightly


could it be anything else? input appreciated. its hard to diagnose it right now seeings it about 12 degrees every freaking day outside and i freeze my **** off laying on the ground, so im trying to eliminate as much as possible while staying warm.

so confused, help much appreciated.

also, if any of you tip guys read this, how much vacuum do you make when in park idling and when in drive idling?

 

IDK about the sound but as for vacuum idle park is about -21ish and drive is -18ish.

Josh

 

I get a bad vibe sometimes from my front cv. It moves in and out. I pull 17-20 in of vacuum at idle and in park.

 

Man, that sound is unlike anything I've heard.
Would you be able to get a higher quality vid or even just audio?

So does the vibration go away above 40?
Have you looked ath the inner CV joints also?

 

thats the best video i can get, all i have is my crummy blackberry. The rattle is very strange...i dont get it at all. definately have a vac leak then because only pull about 15 inHg at idle in drive, and 18 in park. i have a boost leak too im guessing, so that could be it. this is so frustrating.

 

I totally understand your frustration, sometimes the "issues" on these cars can be pretty elusive. I've never heard anything like that sound before. My first thought was exhaust rattling, but, that wouldn't really coincide with speed. It would probably rattle all of the time when the engine is under load.

As for the EVAP leak, are you throwing P0455? Have you checked the gas cap? Most of the time the EVAP leak codes are thrown because the gas cap isn't making a tight seal or it's off completely. If the cap is good, clear the codes and see if it comes back. If not, chalk it up to a loose cap at some point.

 

Ok, the clicking has started, i assume CV, but only clicks when i am pressing the accelerator, is that normal. Also, clicking does not change at all when turning, but does get faster to almost a rattle at highway speed, still a CV, or could it be a driveshaft thing? I get a vibration sometimes when accelerating, but not the vibration and click, its one or the other.

anyone have some tips on what to look for and how to locate my problem? i looked at all the boots quickly, and all are intact. Could it be the differential mount? how would i check that? Any help much appreciated.

 

also, still safe to drive?

 

Vibration sounds like a driveshaft. I assume this car, like most, has counter weights on the driveshaft. I'd check to see if they're peeling off or if they're missing all together.

 

The boots can still be intact and have a worn CV joint. Definitely sounds like an inner. When it's up in the air, try to hold the flanged part of the CV joint, then try to rotate the shaft back and forth and feel for any play.