ibush01

Since late summer I've been having a disturbing issue on my '10 A4 P+. Started around 19k miles (now have almost 22k). Rough, erratic idle rarely at first start but more often at a stop sign or stop light or in park, regardless of temperature or length of drive. Once, the check engine light flashed briefly; it's only reappeared once (this time, tonight, and it stayed on). Several times, the car has shaken violently at idle (it's as if dueling sumo wrestlers are trying to pick up the vehicle from either side).

Dealer checked it out three times now -- told me the first time it threw up some bad fuel codes (I never cheap out on gas, always 93 octane and usually Shell). Techs -- over a three-day period -- performed GFF, reset the readiness codes, and report it "test-drove to Audi specs." Dealer told me to drive through this tank of gas, and see if it happens after a re-fill. It did: about 150 miles into a new tank, it stalled at a stop light. They took it over a five-day weekend, and found "nothing wrong."

I've had about two tanks of gas in since, and suddenly, about 300 miles into the latest re-fill, the shuddering (this is not the infamous steering wheel shimmy -- it can't be) is worse than ever.

Here's what it looks like from the rear:

http://www.youtube.com/watch?v=VJ3SMDAQHdY

What's going on? I'm paying too much money to have this little piece of mind. Thanks for any ideas...

MikekiM@PureMS

Definitely sounds like some bad misfires. I'd scan the ECU again and see what the codes are that's coming up.

It's definitely more than simply bad gas.

gunsmoker

You may have water in your gas tank since you typically get these problems when the tank is not full. Try a water cleaner additive.

Blake P

I would bet your intake manifold is busted. My car was doing the exact same thing and turned out the manifold needed to be replaced. Quite a few members over at Audizine have had the same rough idle issue, with the cheap plastic manifold replaced in each instance.

Strokera4

Hey, my A4 did something similar. I had an intense vibration from the engine occur when I stopped the car while it was in drive. It also happened with even more intensity when the car was in reverse. The Audi dealership "Classic Audi of Westchester" did not want to acknowledge that there was a problem until I forced them to put my car next to another A4 from the same year (09) and put a glass of water on the dash of both cars. My A4 made the water shake as if it was boiling. The other was perfectly smooth. They ended up replacing the engine mounts and the problem went away a bit, but its still there sort of. In my case it didnt make any backfire noises like in your video? Just take your car to the dealership and demand that they fix the problem. Its their responsibility. You did not pay for a premium luxury car to have it sound like an 88' Buick when you pull up...

QUA77R0

+1

I had similar symptoms when my DV failed. It got progressively worse and then the engine light went from flashing to solid and the car refused to restart. The dealer replaced the intake manifold. Apparently the DV is molded into the intake and the entire intake needs to be replaced.

ibush01

Thanks, all, for your help. I took my A4 to another dealer, who at a first visit found nothing and in a second trip (after repeated symptoms) replaced the intake manifold, which they said was cracked. Because some of you pointed to that as the issue, I was optimistic. (And hopeful, since I've been in 07 loaner for days totaling nearly a month since the summer -- and over Christmas).

But after the 'fix,' and after a fresh tank of v-power, I drove the hour north home -- and more sputtering, erratic idle, gas smell, and ANOTHER stall. Another midnight, sub-freezing temp wait for a tow.

Pardon the vent, but I'm ridiculously frustrated: I'm paying $600 a month for zero confidence (and sometimes, zero car). The fact that I'm Googling 'lemon law' (too many miles) and the Magnuson-Moss Warranty Act is laughable. I'm lucky to have a very nice Audi service rep. But...

markinarch

eeek. sorry to hear that. good luck.

Gavin-AudiUSAParts

Call the Audi client relations 800 number (in your owners manual) and layout your experience begining to end in detail. Explain your distress over the situation and demand a resolve.

You'll be contacted shorly after by someone ready to help and able to provide real solutions.

av_audi

When was the intake manifold switched to plastic on the 4-cyl turbo? Did this happen with the first version of the 2.0T? I know that plastic manifolds are supposed to save weight and even deliver better performance, but they may not be as durable, especially in turbo-charged engines that can dump a lot of head in the engine bay. I think it was Ford that had a really bad streak in cracked plastic manifolds in the nineties.I guess if you go with plastic, you can't skimp on its quality.

It is amazing to watch German manufacturers progressively replace metal piping with plastic/rubber hoses, metal manifolds with plastic ones, metal water pumps with plastic ones, and just generally using less and less durable components. The cars seem more trouble free for the typical length of ownership, but not quite as durable for the really long haul.