'06 Impreza 2.5i Wagon vibration

Starting at 70 and going at least up to 90mph, there is a very slight shimmy to the car. The wheels have been rotated and balanced. The car has 2500 miles on it.

The dealer's "expert" can't feel the vibration, but I just had a 900 mile back masage going from LA to Sacramento and back.

The steering wheel does not "twitch" though I can feel the vibration there too.:banghead:

The dealer is still trying to work with me on this, but doesn't seem to have a clue ("That is just how they ride")

Any clues, guys?

See if the dealer will spring for an alignment.

What are the stock tires on the 2.5i? Who did the balancing? Some techs are better than others about getting things really balanced...

I had something like that, and it dissappeared when I got my tires replaced, but to be fair, mine were nearly bald.

Thanks, I suggested that, but they said it wouldn't be showing up at 70, it would happen much earlier.

The tires are Bridgestone Potenza RE92A 205/55 R16 89V

The RE92 isn't exactly the greatest tire out there - it could well be tire related.

Have your rims checked for warps, believe it or not it can happen on cars. Also have an alignment done as Jay suggests.

An additional thought is to have the propshaft balanced - they can be out of balance and if they are can set up harmonic vibrations at certain revolutions or speeds.

More data: At my own expense, I took the car to a Bridgestone dealer and had the tires inspected, balanced and rotated. Then they aligned the car.

Sadly, there is no difference from before.

I drove my wife's car on my usual "smooth pavement" section where my car vibrates, and it is, indeed, very smooth in her car.

The dealership still hasn't managed to hook me up with the factory rep. after 2 weeks. I have started documenting everything just in case I need to start waving the "L" word around.

You said they checked the tires, what about the rims? Have you had them checked?

I talked to the tire shop this morning and they said that they would have seen any real warpage when they balanced the wheels.

I now have an appointment with the Factory Rep, and am researching what other sources could cause vibration. So far:

Out of balance brake rotor (or warped?)
Drive shaft (there are 5) imbalance or bend
Defective shock yielding inadequate damping
Poor matching of the tires to the suspension
Voo Doo curse by my old Toyota dealer (Last two cars were Toyotas, this is my first Subaru)

I am open to further suggestions.

Keep us updated. If you discover the problem, we'd like to know so we can diagnose/avoid it in the future

Starting at 70 and going at least up to 90mph, there is a very slight shimmy to the car. The wheels have been rotated and balanced. The car has 2500 miles on it.

The dealer's "expert" can't feel the vibration, but I just had a 900 mile back masage going from LA to Sacramento and back.

The steering wheel does not "twitch" though I can feel the vibration there too.:banghead:

The dealer is still trying to work with me on this, but doesn't seem to have a clue ("That is just how they ride")

Any clues, guys?


Have your dealer spring for a wheel balance on a hunter gsp9700 balancer.
They are the best and will balanve a tire and wheel when all other fail.
The link below should help you locate one closest to you.
Good luck and let us know how it goes.
MT
http://www.gsp9700.com/pub/search/FindGSP9700.cfm

Thanks, I did not know there were "quality" differences in balancers. ( I should have, I guess). I'll try to hit up one of the sites tomorrow.

Thanks, I did not know there were "quality" differences in balancers. ( I should have, I guess). I'll try to hit up one of the sites tomorrow.


10-4 on the balancers.
It is the best of all balancers.
It balances everything with wheels and tires turning on the car.
It will almost balance a square wheel.
Good Luck and let us know how it goes.
MT

Well, I met with the factory rep, and we drove my car. He agreed that there was a slight vibration. Then we found an identical car on the lot, same tires and all and drove that. THE VIBRATION WAS IDENTICAL! As a result, he says that there is nothing to fix, because that is just how this car drives. He is willing to go halvzies on my choice of new tires, so there is a sincere effort to help. Anyway, to continue the saga, I looked up a nearby shop with the good Hunter GSP9700 balancer and sprung for yet another balance on my own nickle. No change. So, what tires should I buy? Also, in lemon law, is a defective design grounds for a refund?

Check your state law on the Lemon Law, it varies from one state to another.

What driving conditions do you anticipate for winter? What type of driving do you spend most time doing?

I occasionally go to local skiing, chains are sometimes required for 2wd cars but not for 4wd. I would like to have "all season" tires and my research has come up with the Pirelli p-Zero Nero M+S as probably the best choice, though a local dealer says that the Toyo Proxes 4 are equivalent, have some better guarantees and are cheaper.

I checked with a lawyer friend, and he opines that a design defect is as lemon law viable as a manufacturing defect. I will have to check with an expert in the field to be sure.

The problem is this is THE car for me, I just want it to work right. If I lemon it, what else is there that has all these features and performance at anything like the price? Or double!!

I wonder if it's an aerodynamic thing? I've never noticed it with mine, but mine's an '04 and has suspension modifications. That's really odd. I bet it's that dang Alfa nose. As for lemon law, if it's a design flaw then lemon law doesn't apply. However, there are other laws to cover your butt for a design flaw. Possibly a class-action, but I'd hate to wish a class-action on Subaru, whom I dearly love. To make a worthwhile suit, though, you'll probably have to isolate the actual problem.

EDIT: Actually, if you file suit without isolating the problem, you'll have to get multiple witnesses to testify that theirs do it, too. It would be much easier/cheaper to isolate the problem, legally speaking. (SabreKhan is a lawyer)

Interesting you should mention aerodynamics.

First, I came across a guy with a hopped up SPI. He said that a roof spoiler might be the fix.

Second, it was chilly here (oooooh! 60 deg) in the morning and the shaking didn't happen. Two possibilities, first the air would be more dense, and second, the tire pressure drops 1 psi for every 10 deg according to my tire guru.

I have ordered a set of Pirelli tires, and will get them on this weekend. More late breaking news as it happens!

I don't see how it can be an aerodynamic issue - my WRX Wagon doesn't shake.

The roof spoiler a fix? Is he referring to the Wagon roof spoiler or the roof spoiler on his STI?
If he's talking about his STI, I just hope he understands the function of the roof vane.
On the Wagon, I can't say I notice much difference that it makes.

I do notice that the roof spoiler makes my wagon look faster, and that's worth 10hp right there!

I was thinking that the aero of the '06 was really the only thing significantly different from the '04, that's why I threw that out there. Also, 1psi shouldn't cause a vibration (nor should 4 or 5). Especially if you've had the tires balanced, since they're supposed to check the air pressure before they balance.

I was thinking that the aero of the '06 was really the only thing significantly different from the '04.


Please tell me I didn't actually read that:disappoin

What about the different turbo, engine, suspension, transmission, wheels, brakes.....I can keep going.

I just assumed the 2.5 N/A was relatively the same as the 2.5 N/A from last year. Have they really upgraded all that much stuff? (I know they didn't put a turbo on it, and we've already discussed the wheels).

After further research, it turns out that Subaru also changed the valve timing on the N/A motors and re-routed the exhaust a little... still nothing that would cause a vibration based on mph.

Blah, yeah, no turbo...we can only wish :lol:

In the parking lot at work, I noticed the Saab version of my wagon. It does have an overhanging lip from the top of the roof which would give a cleaner air "break" over the top. Should be much smaller vorticies than the smooth curve of my car. Hmmmm!

BTW what is N/A with regard to the engine?

Naturally Aspirated, as opposed to Forced Induction (superchargers and turbochargers).

You know, it is kind of funny that the 2nd car I tested had the same vibration, but nobody else seems to have ever noticed it. You would think SOMEBODY else would have complained.

Even my wife finally could feel the vibration once I turned it on and off a few times by changing speed. Very strange.

Maybe it's the hemorroids increasing my sensitivity?

New tires, problem solved! I got a set of Pirelli Nero Zero M+S rubber installed, and the shake is gone. Anybody need a set of Potenzas? Cheap!

Hahaha! That's completely retarded, but I'm glad to hear your problem is fixed.

The curse of the Bridgestone Potenza RE92 strikes again.....

Smart move to get rid of them.

RE92's were great tires for learning to autocross my WRX. They were grippy enough to use the AWD correctly, slippery enough to teach me the car's weaknesses, and crappy enough that I didn't mind burning them to the ground.