I think it was because he noted he didn’t feel it through the steering wheel. Usually you’ll feel (and see) the imbalance that causes as vibration in the wheel.

I kick myself for not thinking about the motor mounts. My Saab busted two over a period of six months and exhibited about the same symptoms. I think the lesson here is that we all distrusted the CVT and were too willing to find it at fault, or we didn’t listen to his description of the issue.

Edit: I missed the above post about the problem being solved. Sorry about that.

I blew one a few months ago in my ‘05 1.8T (after chipping it), and the resulting vibration does not happen every once in a while. It’s a constant, horrendous shuddering that runs through the entire car (an engine normally balanced for 4 cylinders is only running on 3!). The car will be damn near undriveable.

To me, it definitely sounds like a CVT issue.

psarhjinian : What they are is unfamiliar. Which, in the end, can equate to the same thing. I quite like them, but I’ll admit they’re a bit of a gamble.

I stand corrected.

That Craptatic VT is somebody else’s future problem now, though. Sold it the day it came back from the shop. Wife missed her front wheel drive and hated that Audi like it stole her boyfriend. She gave me her 08 G35 Sedan, and we got her one of the last 3 red 09 TSX’s with nav left in the country for less than invoice.

I hate parting with my fine German automobile, especially since it was finally running right, but if you have ever driven an 2002 Audi A4 1.8T back to back with an 2008 G35, you’d know it wasn’t so bad.

Thank you, Best and Brightest!

psarhjinian, the three people I know who has problems with the coil pack failures received no warning from their dash before their cars died, roadside style. For the record, all had Audi A4s. They were really popular circa 2001-2004ish-ish.

When I feel speed specific vibration in a car the culprit is almost always wheel weights or alignment. I wouldn’t even consider the transmission a source for this if you didn’t have the awful CVT.

For what its worth, Audi has not come up with a work around for the typical CVT issues, and yet they spec. the tranny as the only option on new FWD no-clutch A4’s. It’s bizzare, and makes me think that someone at VAG really misses VW’s well deserved 90’s-era quality reputation. They must be hoping that no one who knows cars or drives hard will buy one.

I have encountered drive-train problems that make noise and let you know that they are getting ready to grenade themselves without ever having had them produce a vibration; it may well be something much simpler.

If he’s saying it’s not something he can feel through the wheel but is coming from the front of the car, it’s probably not suspension, tires or brakes. At least that’s been my experience (worn rotors, bent control arms, shifted belts.

The bushings might be a good place to start, though. If you can get it to happen, does it go away or change if you turn the steering wheel at speed? Any other noises (clunking)?

The infamous Audi/VW coil pack syndrome (CPS) strikes again.

Don’t they normally throw a CEL and or manifest far nastier symptoms than just vibration?

Failed 06B-905-115-R coil packs cause engine vibration all the time. The intensity of vibration on that would also be engine speed dependent not vehicle speed dependent.

Can I assume that you haven’t checked the easy stuff first?

This type of speed-related vibration could easily be a damaged or out-of-balance tire. I’ve also heard of cases where bushing wore out on the suspension (can’t remember if it’s front or rear), and that was the root cause of this type of vibration in a few cases.

The infamous Audi/VW coil pack syndrome (CPS) strikes again.

Check your coil packs as you’re probably about to become stranded roadside if I’m correct….

Some CVTs do come with a torque converter, but since it varies with speed and not with throttle, I’d wonder if the output pulley or something connected to it is loose and hits it’s harmonic sweet spot at 80 once things have slackened due to warming up.

Are you able to get diagnostic information about the ratio the CVT is at when the vibration hits? Or does it happen at a given combination of RPM and wheel speed?

…given the complicated nature of CVTs.

They’re not actually that complicated. Crack one open and it’s actually blessedly simple next to a conventional five-speed auto.

What they are is unfamiliar. Which, in the end, can equate to the same thing. I quite like them, but I’ll admit they’re a bit of a gamble.

I sure didn’t appreciate it

BTW… the CVT is a horrid, evil transmission (just my opinion). The ZF slushbox is a slightly less evil contraption than the CVT. Don’t get me wrong I also despise automatics (I’m in the process of installing the manual gearbox in my A4 Avant because I thought so highly of the automatic). Somewhere between control unit failures… just outright failure and the cost of either of those I decided the CVT is among the most diabolical gearboxes Audi has ever used.