I've got an '04 G35x Sedan with <100K on it, and its vibrating when I get it up over 40 mph. Its worst on the highway at around 70 mph. Its also more noticeable when taking my foot off the gas, without braking.

I've already replaced:

- front rotors & pads
- rear rotors, calipers & pads
- tires & wheels

The most recent was the tires & wheels, which eliminates them as the cause. What's funny, is now, since I went from 17's to 18's, the same vibration is there, but I just feel it a lot more.

Anyone else have similar vibration? Its not just the steering wheel; the entire car vibrates. I should also mention its a New England car, so there's a lot of rust underneath. Had to replace the exhaust (with a Stillen cat-back) because it was 100% rusted out. Control arm bolts just snapped recently when trying to take them out, cause they were so rusted. Rotors were pretty rusted as well when I replaced them.

 

Ball joints on the tie rods can go out causing a vagueness in steering and as it deteriorates it will cause vibrations. If you are also getting some whine that increases and decreases with speed, could be wheel bearings.

 

Wheel hub & bearings bro

Does the car make noise at high speeds?

 

Wheel bearings don't cause the car to shake like that. Bad wheel bearings give out humming noise at hwy speed.

Since you mentioned the car is badly rusted underneath, you should check all the suspension parts like anti-roll bar bushings, ball joints, compression rods, etc. You need to take the car to a good mechanic to troubleshoot.

 

My guess is worn out suspension parts. Possibly compressio rods. Hard to diagnose without looking under the car

 

Thanks guys, while I can't show you what under the car looks like right now, here's what the side looks like with the newly refinished 18's from an '04 coupe:

 

Nice looking wheels!

No use "looking" under your car. The way to check the worn suspension parts is to use a crow bar to apply force to the suspect parts. If the part has too much movement, you need to change it. Go to a good shop and have the suspension checked.

 

Had my mechanic take a look - 3 of the 4 wheels I just put on are bent. Going to take them off and have them straightened.

I'll post back here with an update once the wheels are fixed.

 

so what you're saying is that your 17's were bent also?
Because according to the original post you had the vibration on the 17's and more on 18's

 

That's right - its much worse on the 18's, so they're definitely warped, but there's probably something else causing the much weaker vibration when I hit 70 on the 17's. Could be one of the 17's is warped, could be something else.

Looking at other posts, this guy had issues with both compression rod bushings, and wheel bearings:

https://g35driver.com/forums/g35-sed...s-75mph-3.html

I'm going to either fix the warped 18's, or maybe get some SSR's instead and sell the 18's.

 

I bent two of my OEM 17" wheels. They bent pretty easily after hitting some potholes.

Had them rebalanced and they balanced out fine. I feel a little vibration around 100MPH though...guess that's ok.

 

Check your compression rods and your driveshaft. Pray it's not your driveshaft. I had the same issue a while back and did the compression rods and it was ok. Then it got worse out of nowhere. It would have cost me around 2k for a new drive shaft if I didn't have the extended warranty. Car has been perfect ever since.

 

Hey what were the symptoms you were having?? can u visually inspect the ujoint/driveshaft and be able to tell it's bad? any ideas/suggestions will be appreciated!