A4 2.0T Engine has hesitation, so does dealer

[eblong]

I have an 2007 Audi A4 Avant with a 2.0T engine. Almost from the beginning, the engine has has a 1-2 second "pause" - it's as though the ignition were shut off, but there are no other obvious indicators of an electrical problem - tach stays up, and other guages don't fall off. The intervals between occurrences has been as short as 10 minutes, and as long as 2 months. Typically, it's once a month or so between incidents. It doesn't matter if the car is accelerating or at a steady speed, and the speed doesn't matter.

I have had it into the dealer several times, and all checks out well. Of course, it never happens when they have the car. Since they can't duplicate the problem, they have taken no direct action. There was a reflash that was done for a recall, amd I had my fingers crossesd, but it didn't help. Also, changed gas stations in the event it was water in the gas.

Anyone seen a similar problem, and have any throughts on what to look for? I am also looking for ideas on either how get the dealer to care more, or how to escalate through Audi.

[SINGERCHEME]

I am having the same issue with my 2007 A4 2.0T. I have done some research and I think it is the Diverter Valve. The 2007's come with a series C and there is a more durable series G that is OEM that will better perform. The cause is a tear in the diaphragm. It may seem that you have a rev limiter at 4000-4500 Rpm. The Diaphragm series G costs around $65 and is very easy to replace with a lift or on jacks.
Good luck!!!

[eblong]

Thanks for the info. What I get is more than a rev limiter effect. It actually feels like a momentary loss of ignition. In the old days, I would have bet on a coil breaking down. The idea of a bad diverter valve is very interesting, though, and I will follow through on it.I am traveling overseas at the present time, so the car is sitting here waiting for my return.

Please let me know how you make out. I will continue to research your idea and follow up more actively when I get back.

[SINGERCHEME]

The DV may still be part of the equation.....but I finally got a check engine light this week and the dealership checked into it. They are telling me that it is a variocam failure. If you google this you will find all the same symptoms (mostly porsche forums). The dealership is replacing the cam system and I will keep you up to date on the condition.