Anyone have a guess why when I get to 70+ mph my ride gets a little bumpy? I do know I need new tires, could that be the reason? I'm just driving it right now before winter time and I garage it. I'll get new tires when I break it out next year. Also, the big plastic cover that goes under the car. The peice you have to take off to change the oil, that part got all torn up b/c of a stupid nail on a 1 lane bridge. So I took that off. Could that be causing my front end to shake a little?

Any help would be appreciated, thanks

 

tires slightly out-of-balance could cause it. tires don't wear uniformly, so this could be it. as there is abs in our 350z's, you probably couldn't have flat-spotted the tires during braking, but parking for an extended period of time could do it easily.

 

i doubt the plastic cover is making your car shake, if anything you will just be able to tell if you are leaking fluids now

 

don't worry about it now, it sure isnt the plastic. Wait till next year, throw the new tires on and go from there...

 

Dude, same **** as me, I need new tires..I think its that, my friend has a G and he had the same **** about 80 until he changed tires/alignment/balance.

In Az/NV/CA you need an alignment like ****ing twice a year..

 

Tires.
Tire pressure.
Springs.
Struts.
Not sure.

 

After all the **** you say you've gone through with your tires, I'd say it's obvious.

 

Did you check the blinker fluid level???? Just a thought...

 

Tires

 

Im Having similar feeling at 70-80+ and I have brand new tires.... Think its maybe the weights or balance on the tires? Or maybe I need new suspension I have been dropped on stock struts with Tanabe springs for like 3 years... Need coilovers

 

on bumpy roads i would get "float" at around 80, id hit a bump and feel the back end slide around, coilovers fixed the issue

 

Always happy to help. If you have other questions please don't hesitate to waste my time.