High Speed Pulsating

In the Z, at any speed over 75 or 80mph, it feels like the car is vibrating, not all the time, but like on for a second, off for a second, on…off…etc…

it’s wierd, i really dont know how to describe it without giving somebody a ride to show them…just sounds like a hum noise that goes in and out at a steady beat, about a second or two between each pulse…

any suggestions? anybody wanna go for a quick ride if you think you can diagnose the source of the sound, or if it’s even anything to worry about? could it just be the tires? they’re relatively new, less than 10,000 miles on them, not driven that hard, Yokohama AVS ES-100’s

does it happen if you turn the wheel??

Check for any play in the wheels. Could be a wheel bearing. If it’s not a steadying shaking I’d say it’s probably not wheel balance related. Since it appears it’s not only when braking I’d say it’s probably not warped rotors either.

the steering wheel doesnt vibrate, it’s the whole car that makes like a humming noise…

and no i didnt think to pay attention if it occurs while turning the wheel at 80+mph…then againk i dont get to turn the wheel too often at 80+ mph lol so next time i’m at it though, i’ll be sure to listen/feel for it again…

when i say turn, i really mean just a slight pressure to one side, just enought to lightly swerve within your lane. That is the first step to weed out if it could be a wheel bearing… if it is the whole car shaking, i would be more inclined to check the balance/alignment

it’s the whole car it seems, not centralized over or around any one corner, so i’m not sure it would be a wheel bearing…

and i thinnk the alignment is ok because on a flat surface it goes perfectly straight…and tire wear seems very good and very even all around :gotme:

Sounds like the driveshaft. I can’t remember if you have a Z1 shaft or something else in there, but it’s possible the Z1 wasn’t balanced properly.

i was thinking something along those lines as well…and i still have a stock driveshaft, any recommendations on what to do and where to do it?

u-joint?

and also…would something like this be a problem that will continue to get worse, and eventually cause HUGE problems? or is it like the nissan lifter tick…annoying, but no problem beyond that?

How do you still have a stock driveshaft? The NA and TT shafts are different, and you NEED a custom one to do a TT swap into an NA… I though I told you this?

nope never heard that…and it seems to be working fine up to about 80mph… :gotme:

what should i do?

if it is a u-joint and it does pop you just loose the abilty to drive cause the driveshaft is on the ground.

Oh wait, my bad I was thinking you had an AUTO NA before :ham:

I would definitely go out and buy a 1-piece driveshaft. I know I had vibration issues like this on my NA (so have many others on 100k+ driveshafts) and the new shaft solved them.

Get the proper drive shaft for your application!!! or a safety loop ASAP

:tup: word…i’ll have to wait and see how much help Z1 is willing to provide since i’ve proven that the car has/had bad compression…

after that, given how much i have left laying around, i may be able to afford a 1 piece…given that’s my problem though, i’d still like somebody to take my car for a spin or somethin to see what they think

and other than Z1, who makes a decent 1 piece driveshaft for the z’s?

Well there is a company that sell them on eBay, but I’ve heard both good and bad things about them :gotme:

mine used to do the same thing, vibrated steady at 60-65 then when i got past it would stop. threw in a 1 peice driveshaft and solved the problem. I had one made near my house for 270.

i’m looking at the AMZ steel driveshafts, 17lbs as opposed to 30lbs stock :tup:…the one they make seems ok, i hear lots of good things about AMZ, and its $10 less than the Z1 driveshaft :tup: lol

but then they also carry PST driveshafts that a bit more pricey, but come in aluminum and carbon fiber if i like…tempting…

definatly sounds like recripricating mass, tires or prop shaft