Weird vibrations at 65+

[stephen240]

So here's the gist of whats happening. At 65+ when I cruise (ie not stepping on accelerator) I'm good but I do get a little bit of vibration in the front wheels. Now when I step on the gas the driver side wheel vibrates like a mofo all the way too 100, then the vibration is vibrating so much it seems gone. But around 70-75 I let off the gas and it vibrates very minuscule, but againg I step on the gas and vibrates like a mofo again.

Next I got in a wreck the other day but it was just cosmetic really and it was on the passenger side not the driver (where the vibration is). Wheels did lock up in the fronts to skid into him. So I'm thinking possibly worn spots on my tires? Maybe? I know I need new tires, but could this be the problem? i don't see any obvious signs of a worn spot, but who knows.

Ball joints are all good, tie rods are okay. I'm no noob to cars, father was a mechanic for 16 years and I can take apart anything put it back together, and diagnose just about anything. I just currently got promoted and working 60+ hours a week so I don't have time to put her on the lift. So just looking for some opinions!

Oh btw the wheels were balanced and rotated about 500 miles ago, if that helps.

Thanks!

 

[Travis96GS-T]

It could definitely be the tires. I had the same thing on my old car. I had to lock the wheels up to avoid an accident and had an uneven spot on the tires as a result. The wheels would vibrate from about 60 to 70. Once I replaced the tires it went away.

 

[cheap90gsx]

I've experienced vibrations from warped rotors. But that doesn't seem like your problem.

 

[lccynmbr13]

Your tires are out of balance my friend. 65mph+ vibration is almost always a balance issue. If you don't notice the vibration at the same rpm in lower gears which helps rule out the transmission it's almost a sure thing. If it's not wheel balancing then you may have a tire separating but that would imply a vibration at almost all speeds.

 

[TunaTalon]

A vibration that peaks around 80 to 90 MPH and is lesser at higher and lower speeds is from a wheel/tire out of round or out of balance.

When the frequency of the wheel rotation matches the resonate frequency of the chassis the vibration will be at maximum. If the peak vibration is at 90 MPH and you have stock diameter tires then your chassis resonate frequency is 21 Hz.

 

[reno23]

I had the same issue with vibrations at 120-200kph. After checking up on everything it could have been, tires, wheels, suspension....I realized that my "DIY" Solid motor & transmission mounts were warping and flexing. Replaced them with new mounts. No vibrations, like before, until i hit 220kph and fuel cut hits the car like a wall.

 

[DSM1G90]

Also with agreeing with tires, you also could have cord separation on one tire.

Cord separation is when the cord of the tire has separated from the rubber and air gets inbetween-looks like a bubble.

Raise each end up and rotate the tire and see if any sudden difference in how the tread level looks like when you look across lengthwise the surface of the tread.

If you see a sudden bump (a raise in the tread) while rotating, cord separation has happened and it's asking for a blowout.