post

Any thoughts, bright ideas, educated guesses?


Thanks

 

Rev the engine in neutral, standing still, is the vib still there or gone? This will help you to isolate the problem between engine and drivetrain. Also get the car up to speed on the highway, put it in neutral, and take your foot off the gas. Now your drivetrain is spinning but the engine/TQ are at minimal speed. Your motor mounts/tranny mount isolated the engine from the chassis. Maybe your tranny mount isn't completely busted but still damaged.

 

OBE1 listed some great ways to narrow it down. If you're still running the stock tranny mount, it wouldn't surprise me if it's on the way out. They don't seem very durable, especially if they're exposed to oil/tranny fluid. My Energy Suspension piece has survived 6 years now, so that would be worth a look.

 

Thanks guys, I'll check that out when we get out of the house finally. I don't remember there being any vibes when just revving the engine but definitely will double check that. It is just a stock replacement tranny mount. Didn't know they sucked before I had it replaced. Now I think I know my way around the car enough to swap it out next month regardless! Anyone else? I'll post up what I find later.

 

I'm not a fan of the ES tranny mount, I ran one for about a year and it adds a lot of vibration into the interior. I switched to the 1LE mount; stronger than the stock mount without being harsh. I believe GM stopped making the stock mount a while back and now only sells the 1LE mount (can you say design problem).

 

Ok...Iforgot to mention a few things. Thanks to the wife for noticing! This vibration occurs when I'm racing or get on it pretty good like hit passing gear on the highway. Its a STRONG vibe and sometimes I can feel a light version when decelleration from highway speeds. Also, I don't know if this relates or not, but I have a whine that comes from the rear ONLY on decelleration. Sorry to have mislead or anything if I did. I should be getting the ol' driveshaft rebalanced soon just to be sure about its condition, the u-joints are a few months old, I noticed the rear tranny seal looks to be leaking a little bit. I figure the vibration could make that happen, but have no experience to base that on. Anywho, hope there's still some ideas to look at!

There is no vibration when in neutral/park and revving the engine up.

 

hehe, sounds like my car. Granted an Energy Suspension poly mount is sitting on the desk right now waiting to be put in.

But I also have a big thump if i step on it, my stock tranny mount is 11 years old now, gasp!

if your tranny mount is on its way out, it would do that, the noise on decelleration, do you have gears installed?

 

Well i know im not the only one. my car has been doing the EXACT same thing for about year now. I had it to dealers and tons of shops, and everytime nothing is wrong so they say. THe car drives fine, hell it even performs great. Im just figuring it something thats out of place that will either brake before to long or just go away, lol. If you find out what is let me know.

 

sorry guys, didn't realize I'd lost my own thread! Haven't found anything yet, but haven't had a lot of time to look. Don't have gears in, just the 3.23's it came with. What about if the flywheel was beginning to crack or had a fracture around the bolt pattern? My old 'wheel had this pattern on one side and nearly all the way around on the opposite side too. Thoughts?