Hey guys and gals,

Just came across this problem yesterday into today. My 04 z seems to have a harmonic shutter coming from the rear. It didn't really set in till today when i started to notice that my gas mileage was def lower than usual.

Anyone else come across, or heard about this? I'm calling the service department monday ASAP. This should hopefully be covered under my nice cushy 100k b2b & Powertrain warranty....(knock on wood)

The tires are still in good condition and really have a good amount of tread left before they need some replacing. I took a look at the PSI as well and everything is up to spec.

I can't really thing of anything else...

IDEAS!?!?!?!?!

 

Drexelnick,

I have an 04 Roadster. I also have a shutter. I was thinking that it was caused by tires and as the car needed new shoes I was hoping that this would cure the problem. It didn't.
My shuttering begins as I approach 70mph and then subsides at about 80mph. It is there at all speeds, just not as noticible. if you hit a bump at less than 70mph a high frequency, short lived shake will rattle the car. If I drive at a steady 70mph I can actually see the cowl and the rear view mirror shaking.
When this is happening I am constantly trying to analyse what might be causing this (takes the fun out my driving experience). I have gotten the car up to speed and put in neutral and shut the motor off and let it coast to eliminate the engine and tranny from the mix. The shutter is still there. So, that leaves the drive shaft, the rear end, axle shafts (and universal joints) and finally the wheels and tires.
On my car, at this point I'm begining to think that I have a bent wheel. Instead of rolling true, it might be rolling in an orbit. I'm going to look at that today.
If and when you find the cause, please post what you've found and I'll do the same. Good luck.

Bananas!

 

Ok, well i think i might have figured it out...or at least made some serious progress!

So i had a decent drive home today and once again the Z started to shutter. By the time i'd gotten home, i turned off the car and pulled the e-brake. To my astonishment, the car rolled forward! So i pulled up a little bit more and it stopped.

This got me thinking...could the rear breaks be causing this!?!?! i kneel back by the rear wheel and i smell something that def isn't supposed to smell back there. Then, along with the smell, notice that it's really really warm in the wheel well. Upon further inspection, notice it's coming off the breaks mainly from the rotor...i decided to see how warm with my finger....PSSSSSST FIRE HOT!!!!

Needless to say, at the expense of a burned finger, i might have solved this problem. Now it's off the the service depot to use that handy dandy warranty of mine....

Bananas....Hope this might help you out a bit. I'm thinking it's getting warm enough that your rear rotors might start showing signs of warp. Take a look next time. If theres obviously a good amount of heat coming from inside the rear wells....there's your problem, go get it checked out!!!

 

B R A K E S.

Dear muffin.

Anyway, I notice a shudder at a certain RPM, not any given speed. It happens around 2200-2500rpm's.

 

To the OP does the shuttering happen only while your applying the brakes? If not then your theory of warpped rotors is incorrect. Also how would a loose parking brake cable that can't hold the car in place, cause your calipers to heat the rotor up enough to warp it?

 

Bananas!, your problem is definitely either poorly balanced wheels or a bent wheel. Wheel vibrations will always make themselves noticed (if they weren't already noticed) around 70mph on most cars today.

 

Corradoslc7,

I bought the car used from a Mercedes dealership in Daytona Fl. The rims had some curb rash on them. The dealer had already put on a new set of Michelins. They also agreed to have the rims reconditioned a (scratches filled, rims painted), did a real nice job. Because the tires had to be removed from the rims and re-installed I requested that the wheels be re-balanced, which they did. There is the slightest hint of vibration at 70mph now. I only notice it because I concentrate to determine how bad it is. I'd say at this point it is about 90% better. I can live with it.
Drexelnick, Didn't mean to hijack your post. Hope you solve your problem. If all else fails, maybe have the wheels re-balanced. Good luck.

Bananas!