vibration over 65mph

[Kimmers]

Hi All,

I recently purchased my 02 PT and have had this vibration whenever I drive it over 65mph. The dealer balanced the tires twice and claimed not to feel a thing when test driving it. The car has 17" Goodyears on it and they appear to be in good shape. I am baffled as to what to do about it. Any thoughts? Thanks.

[CREWZIN]

When the dealer balanced the tires, did they put them back on the same corner they came off of? If so, I'd rotate them back to front to see if the vibration changes. Can you narrow it down to the front wheel vibrating or the floor pedals and drivers seat? Since the dealer had the car on the lift, did the mechanic look for any notable signs of wear and tear on the front end parts?

[Matt42]

Originally Posted by Kimmers

Hi All,

I recently purchased my 02 PT and have had this vibration whenever I drive it over 65mph. The dealer balanced the tires twice and claimed not to feel a thing when test driving it. The car has 17" Goodyears on it and they appear to be in good shape. I am baffled as to what to do about it. Any thoughts? Thanks.

Did the dealer drive it at 65 MPH? Always a good question to ask. Most test drives don't get that fast.

Some brands of tires, once they start to separate, become unbalanceable. They will just keep separating until they just come apart. This is also true of any good brand of tire that's been allowed to run underinflated. They get internal damage that just causes them to slowly come apart from the inside out.

Crewzin's question is also spot on. Did the tires get rotated in the process, and did the vibration stay the same? If coming from the front, it -could- be CV joints and not tires.

Some things I'd ask you. Having a good handle on them yourself can help a good shop narrow down the problem.
-What dealer balanced the tires? Car dealer or tire dealer?
-How old are the tires? There's a date code on the sidewall. Do a google search to figure out how to decipher it. 5+ year old tires can act "funny".
-How many miles on the car? Do you have it's service history? See comment about CV joints.
-Is the vibration only over a narrow speed range, such as 63 mph to 68 mph?
-Is the vibration dependent on a particular road surface, like freeway concrete?
-Where were the Goodyear tires made? USA? China? Seems to be making a difference.
-Can you make the vibration stop by lightly resting your foot on the brake?
-When you step harder on the brake, does the pedal pulse?
-Do you feel the vibration in the steering wheel, or in your seat or both?
-Does the vibration go away when you take your foot off the gas? (See comment about CV joints.)
-Does the vibration get worse, get less bad or not change at all on curves?

Based only on what you are telling me, my "not knowing anything better" guess is that you have a bad set of tires.

[Kimmers]

Guys,

Thanks for your thoughts. The tires were balance by the car dealer. The car had 68k on it. The vibration occurs over 60 with varied intensity and is not as severe when doing gentle curves to the left. The brake pedal does not vibrate. It is primarily felt in the steering wheel. I cannot say how old the tires are, but I was not ready to run out and replace all of them on a hunch and find out later that I wasted the money. I also read over tire comments from other postings. Given that tire question, where would you go and what brands would give you a good ride and reasonable tire life? I do appreciate your quick response. I am pretty handy and since this is a second car, I'm willing to do as much if this as I can. Keep upi the good work!

Kimmers

[Matt42]

Keep in mind that this is guessing 2000 miles away, after dark.

If the tires went back in the same places, the worst is probably the LF.

If the Goodyear tires on the car are made in China, you will be replacing all of them sooner than you expect. Ditto if they are more than 5 years old in any brand.

Have them checked by a reputable tire store that does not have a reputation for selling you a tire even if you don't need one.

A quick and dirty test is for you to gently run your hand circumferentially on the tire's tread to see if you can feel lumps. If you do, the tire has a separation that's growing and is in danger of flying apart. As the separation grows, it will balance OK for a while, and then go out of balance again.

If you have a second PT available, temporarily swap the tires and wheels. If the problem stops, buy tires.

Brands I like are Michelin and Pirelli, then Continental, in that order. Those do best in my experience where highway heat is bad, like in Arizona. People in cooler places report success with Yokohama, Toyo, more recent Goodrich and Falken. Others like Hankook and Kumho but for myself, I would NEVER use them. Strangely, inexpensive "Warrior" tires do amazingly well here. They are made in China by an outfit called (I think) Shanghai Michelin Joint venture.

I worked at an independent tire store during the Firestone 500 debacle in the 1970s. It really colored my outlook on tires. Even when I couldn't really afford it, I paid the extra money for Michelin tires for my family and I never regretted doing so.