2003 Avalon Rough Ride

[jk7k2b]

My wife's 03 Avalon has been exhibiting a bit of strange behaviour since we bought it. At first, I thought it may have been tires since they appear to be a semi-hard compound and are beginning to show what appears to be dry rot symptoms. The problem manifests itself as a type of "surging" while driving that exists even when coasting, and seems to get a bit worse the longer you drive. My first suspicion was brake related, possibly warped rotors, but the brake pedal does not pulsate and the symtoms exist without the brakes being applied. I then suspected CV joint issues, and the problem does seem to be reduced when, and immediately after, turning. The funny thing is that usually CV issues shows up during a particular directional turn whereas turning either right or left has the same effect.
I know it's difficult to diagnose these types of problems just by description, but can anyone think of something I might be overlooking?
I am going to have new tires installed tomorrow, so I'll have them check things out while the car is up, but I'd just like to be prepared for anything they "throw" at me.
TIA,
John

[TrailDust]

I've never heard of that particular problem. I'll be interested to know what the cause is....

[jk7k2b]

Yes, it's got me stumped! It is exactly like the feeling of a warped brake rotor during a moderate stop - kind of like a "drag - no drag - drag - no drag" feeling. Very strange, but I will keep the thread updated.
John

[jk7k2b]

Installed a set of Pirelli Pole Position tires and most of the problem is gone. Wife says she still feels "vibration" on occasion, but I have not been able to experience it myself. I'm wondering if shocks/struts could be worn and transmitting a bit more road vibration than normal. I do sense a bit more road feel than I think should be present in this car (daughters 2001 XLS is much smoother ride) but this is an XL with not as much luxury equipment.
But I still have that nagging impression of a bad wheel bearing sensation.

[BiXLL]

What about steering rack bushings or even the rack itself going bad?

[jk7k2b]

I never considered that since the steering is pretty tight and the car handles well. Just has this quasi "grinding" or rough sensation when rolling.

[BiXLL]

Originally Posted by jk7k2b

I never considered that since the steering is pretty tight and the car handles well. Just has this quasi "grinding" or rough sensation when rolling.

I'm sorry, I misread your post, I was thinking it was when turning. Ok pretty much ruled out rotors do to no judder. The only thing that I can think of that would give you the "grinding" or "rough" sensation while rolling would be a cv axle joint, or a wheel bearing. All though my daughter had an escort I was sure was a wheel bearing and believe it or not was a tie rod end.

[maun]

Is your engine surging? You may want to check/replace the PCV and spray some cleaner in the air intake area. The chemical cleaner is specially made for air intake area after the filter. I am trying to say that if it is the engine surging, then the air fuel mixture is mess up due to air recirculation in the EGR and EVAP. This system brings in the unburnt carbon back into the engine to burn again for to cutting down on the pollution. After a while this area get real dirty and needs some solvent cleaning.