Intermittent Vibration, Belt Shifting?

[javacontour]

I'll probably cross post this to the Maintenance and Repair section.

I took our 2002 Sienna to my trusty mechanic for a check-out before oilBabe takes it to Dallas, TX next week to visit her brother, SIL and their new baby with our kids and her mom.

The van has a very intermittent vibration that may or may not happen during a trip. It might happen 1/2 hour into the trip, or may not happen for an hour or so, or may never happen. When it does, the wheel can shake severely, but not so much that one loses control of the vehicle.

Then, it goes away.

So I asked them to look at the van to see if anything is obvious, alignment, balance, broken or bent suspension parts, struts, etc.

They did the inspection and found nothing horribly wrong, re-balanced the wheel/tire assy and gave it back.

He mentioned it may be a slipping belt in a tire.

I really can't find much on a slipping belt on line, so I thought I'd ask about it.

oilBabe is taking the van to work today to see if the problem recurs. If it does, I'll swap two of the wheel/tire assy from her Camry to the van and drive it again to see if the problem stays or goes.

But other than this method, are there any tips or hints on how to track down such a fault.

Second, what is going on if there is such a fault.

Finally, we bought the van used, so if it turns out to be a bad tire, will Goodyear still warranty the tire, or are we on our own?

 

[CapriRacer]

Java,

Shifting belts are a myth. Belts are surrounded by rubber and once "cured", they stay in position - even if the tire is separating internally.

But your problem isn't tire or wheel end related. Vibrations from these sources are constant. Acceleration, braking, coasting, steady speed - always there.

This sounds like a worn component that is causing a "shimmy" - a rapid sideways oscillation of the hub assembly. This is common for vehicles that have large amounts (relatively) of caster.

I suggest you have someone else look at the vehicle. In particular they ought to look at ball joints and tie rod ends. Looking at the alignment wouldn't hurt either.

 

[javacontour]

Thanks,

I had read that too, and wanted some knowledgable confirmation.

oilBabe called back and said there was some shimmy under braking, but other than that, the drive was better. So I'm planning to pull the wheels to see if there are any obviously problematic brake components.

I just don't understand how something can be a problem for say 5 miles at what seems like a random point in the trip, and then get better and not recur for hours later if ever during that trip.

It's likely impossible that a mechanic would catch it, unless one could get it there while it's doing it, and if you are too far away, it's just as likely to go away before you get there.

They did inspect the suspension components, but didn't do an alignment, so perhaps there is fruit in the alignment suggestion.

Thanks!

 

[Audi Junkie]

Intermittent could be different smaller vibrations coming in and out phase with each other.

 

[javacontour]

I took it for a long drive last night, and after about 15-30 minutes of driving, the vibration began. It took a while, but it was there, and didn't go away until after dropping to a lower speed, like from 70 to 40-50 MPH.

The other thing I noticed was that there was some really bad shudder under braking at speed.

Swapped the front tires to eliminate that, such as a tire growing as it heats up or shrinking, or whatever. Same behavior this morning.

So I went off for new pads and rotors, brake cleaner, hardware kit. (I already had blue caliper grease.)

oilBabe has had it out for the past 30 minutes and says it's much better.

I would have sent her in her car, but I found a torn CV boot when I was swapping tires around, so I parked her car in the garage. It's going back to the shop on Monday as they installed this axle back in August or September.

I guess it was good I looked at that. That's the only issue we've had with the Camry, but it's been a recurrent theme. First a torn boot that was repaired, and then 75K miles later we had the axle replaced, and in 10K miles it tore a boot.

Not bad for a car that has traveled the distance light travels in one second, 186K miles.