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I recently got an oil change on my 2008 Audi A4 Quattro. Now I notice that when I am cruising in 3rd, 4th, or 5th gear (but not 6th), and I am at about 1200 RPM, the tachometer is not stable.

The speed is stable, but the car starts to shake back and forth, and the RPMs dance between 1200 and 1400. If I use the Tiptronic shifter to move one gear down, it all disappears, but the RPMs jump to 2200 or so. Then after few seconds of cruising, the transmission shifts up a gear, and it all starts again.

Any idea what this could be?

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How many miles are on the car? –  Paulster2 Jan 17 at 13:46
    
95k give or take –  KingsInnerSoul Jan 17 at 13:53
    
Also, I have had the car for 9 months or so, and haven't changed spark plugs yet... Can that be the cause? I am just wary that the mechanics at the dealership did something to make me come back and do a more expensive fix... –  KingsInnerSoul Jan 17 at 13:56
    
As a Note: There is a reason the dealership is so lovingly called a stealership. Usually though, if a dealership is going to cause a problem, they will ask to fix it. The service tech and mechanics make more money (higher percentage from the job) when they find more work than what you bring them. –  Paulster2 Jan 17 at 15:03
    
As for your issue, I'm wondering if there is an issue with the transmission and/or torque converter ... It sounds like something is slipping because you said you maintain speed. This could be a programming issue in the computer. I don't know if applies, but you could check the links out of this thread and see if it helps. Seems there are some oil/computer changes which may be pertinent. –  Paulster2 Jan 17 at 15:21

1 Answer 1

Sounds like a transmission related issue. I would take it back to the immediately if it wasn't doing that before they serviced it. I doubt anything they did caused the problem, but if it did the quicker you take it back the better.

A slipping torque converter clutch would cause similar symptoms, which could be caused by a bad solenoid, bad torque converter, cracked case (internal), etc. Now that's not the only thing that can cause that symptom but it's the first thing that comes to mind.

It's possible that there is a programming update for the car's computer that may address the TCC issue as well.

I wouldn't worry much about the wrong billing information being in the computer, that's just used for billing. The computer they use to check for updates connects directly to the car so that would be correct if they hooked it up, however on just an service they wouldn't normally do that. Depending on the dealer they may or may not check the vehicle for updates, service bulletins, and outstanding recalls. They use the VIN for that if they did and if the VIN was wrong on the repair order then they may have checked the wrong VIN when checking.

Again I would take it back to the dealer immediately to have them check it out.


Edit

Based on your comments this isn't related to the recent repair. There is a TSB (Technical Service Bulletin) that addresses your concern.

Condition Customer may report shudder or RPM fluctuation while at cruising speed in 4th, 5th, or 6th gear. Technical Background

Torque convertor clutches may have excess slippage while cruising.

The solutions range from updating the TCM (Transmission Control Module), Fluid change, and replacing the torque converter.

This doesn't mean that that's what's wrong with your vehicle but it's the place to start looking since this is a known issue.

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It has been like that for over a month now if not two... –  KingsInnerSoul Jan 17 at 20:31
    
It is a 2008 Audi A4 Quattro 3.2L Sedan –  KingsInnerSoul Jan 17 at 20:32
    
@KingsInnerSoul I updated my answer based on your comments –  Larry Jan 17 at 20:52
    
How come they did not do a recall on this issue? And how come it suddenly appeared after the service at the dealership? –  KingsInnerSoul Jan 17 at 20:59
    
@KingsInnerSoul You said it's been that way for a month or two. It's not a recall, it's a TSB. They don't just randomly check all the TSB's for your car when you take it in, there are many times a hundred or more per car. –  Larry Jan 18 at 5:43

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