GTXZ06

2004, z06
46K, manual

3 questions:

1 - once the car starts moving, it seems fine, no vibrate or shaking but at idle, the car seems to shake and vibrate a little, you can feel it coming from the engine, ( it only does it sometime) is this normal ?

2 - i notice it is more difficult to shift into gear when the car is cold, once the car warms up to normal temperature, shifting is much more smoother, is this normal?

btw...i had already change the trans fluid.

3 - I read and heard of the common issue with the harmonic balancer, if i remember correctly, this only effects early c5s and not the 2003s and 2004s? is this correct?

i am worry this may be related to the vibrating/ shaking but no chirping sounds.

Thanks in advance guys.

Macleod52

I have an '01 M6 and notice the same things as you describe in 1 & 2. I assume they are normal.

I'm fairly certain the harmonic balancer affects every year. FWIW my '01 has 92k and shows no signs of wobble (Knock on wood).

GTXZ06

thanks, that help eased my concern.

Macleod52

I find that shifting into second then first helps. Also it couldn't hurt to do the "ranger" method and clean out your clutch fluid.

grantv

Yes, nice little chop.
Yes, a tiny bit; better with the Amsoil.
No, all years AFAIK. Check if you see any irregularities. My 04Z also around 46K, HB seems fine.

wcsinx

Normal, the cam profile used in these engines tends to impart a slight "shiver" at idle. (The Caddy guys used to complain about it a lot)

Sort of, I never noticed any difference in shifting cold v/s hot back when my tranny was filled with Dex 3. When I started using Pennzoil Synchromesh (which FYI I highly recommend) I did notice a distinct difference. Cold shifting felt stiffer and more sluggish than warm because of the increased viscosity. Then again, I live in FL. If you're in a colder climate it's highly likely you'd feel the same thing with the original Dex 3.

Balancers are, generally speaking, a wear item. I've replaced many on Gen 1s. My LS1 balancer is holding strong though at 106k miles. It's best to inspect it periodically instead of waiting for it exhibit symptoms. I like to (gently) hold a long screwdriver on the face of the balancer while the engine is idling. If the balancer has started to separate, you'll feel the push on the screwdriver as the high spot rotates past.

3sACROWD

There is some level of shake to the engine as others have stated. Every once-in-awhile, the connection between the air cleaner and intake slips off on my car. Make sure yours hasn't done the same. If it did, you are getting unmeter air into the engine which causes a rougher idle.