Yesterday I noticed that compared to my normal idle (which is a chattery idle since I've had the A4 from day one, not unsmooth, but not purring) I felt like I was in a diesel. Not Mac truck bouncing type, but there was noticeable vibration.<p>Then I thought I noticed some roughness in the 2800RPM range in 2nd and 3rd gear, but it was icy and snowy yesterday so I wasn't using acceleration, like today after everything is melted. So today I notice roughness under acceleration in 2nd and 3rd gear - quite noticeable unlike yesterday. It's not loss of power roughness, it's a pattern type roughness like loss of power in one cylinder.<p>So now tonight the check-engine light doesn't go out after I get in the car after going out to dinner. I went to get fuel after that and noticed that the mileage is down. 280 miles for 14 gallons. Usually it's 320-340 miles (never less than 320, rarely more than 240).<p>I know that this 10% Ethanol crap they make us use here reduces fuel efficiency, but this is lower than normal.<p>Anyway, can I drive the car over the weekend, or do I wait until Monday? Do I take it to the dealer 5 minutes away, or to the dealer I bought it from? My dealer will give me a car, the other dealer would give me a hard time unless I said, "Uhh, Audi Guaranteed Mobility?"<p>I can see this happening at 2000 miles, new car hiccups. But I've never had a check engine light. Just makes me suspicious of the future.<p><br>Chris Murphy<br>1998 A4 2.8QM Pearl<br>

As a matter of fact, I just picked up my car from the dealership today for the most recent one. They have all been fairly minor inconveniences:<p> 1) 9000 miles: diagnosed as "bad gas"<br> 2) 13000 miles: bad "temp sensor"<br> 3) 22000 miles: new spark plugs needed<br> 4) 35000 miles: "eng vac leak - evap line"<p>All were repaired fairly easily under warranty. Apparently, these cars have extremely sensitive emissions test systems. I've been told that it's no big deal to drive with the light on IF it's not flashing. If it's flashing, though, it's a serious problem.<p>Like you, I live 5 mins. away from a dealer, but I go to the farther away dealer where I bought my car so I can get a loaner. I'd suggest getting the loaner, so you can leave them plenty of time to test the car cold and adequately diagnose the problem.<p>BTW, despite these inconveniences, I love the car and wouldn't trade it for anything short of a new S4.<p>Rich D.<br>'98.0 A4 2.8QM<br>

This is insane. I don't call having to drive down to the dealer (1 hour for me) four times for these problems minor. And if they are occuring this frequently and with such a new car, your A4 will not be a cheap car to maintain after the warranty is over.<p>It's not a sensitivity issue when they aren't just resetting the system. In your case they are replacing stuff that would cost MONEY if it weren't under warranty. Something was in fact wrong.<p>I'll check with the local dealer and see if I can get an Audi Guaranteed Mobility loaner car. If not I'm going to have to question what Guaranteed Mobility means.<p>Thanks for the answer though.<p><br>Chris Murphy<br>1998 A4 2.8QM Pearl

...he drives down my gravel driveway. It then goes out after a couple days and stays out until the next trip down my gravel driveway. Figure that one out! The VW dealer can't find a problem. I think something is loose and gets rattled on the driveway, buit nothing has been found. Hope you get that taken care of. Those lights are kind of annoying to look at!<p>Charles<br>

...neck.<p>And I didn't even mention having all four brake rotors replaced under warranty (though I've used them pretty hard at track events), as well as ball joints in both front wheels, which they said would have been a $800 job if not under warranty.<p>I'm sure I'll purchase an extended warranty when the time comes, which will give me peace of mind for ~$2,000. This will be less expensive than the cost of trading for a new car, particularly since I have about that much in performance equipment already installed. <p>I probably could have gotten superior reliability from an ES 300 or an Acura TL, etc., but they wouldn't have been near as much fun to drive, nor would they have Quattro. I'll take my A4 as is.<p>Also, many others on this board claim to have had few or no problems, with as many or more miles on their cars as me. Therefore, my A4 is not necessarily typical in terms of number of problems.<p>Rich D.

ANY obdII car is going to detect these things. This is a positive thing in my mind because they can actually detect what is wrong with the car!<p>I can't tell you how many times my old japanese car had "undiagnosible" engine problems (pre obd), far more problems than his (and the were only partly covered by the warranty).<p>Any car will have bad gas, fouled plugs or burnt sensors. You probably had them and just didn't know. It's common for the computer to adjust to a default map. If the light is not blinking, steady on, you can and SHOULD drive it 4-5 times after it comes on, because it often checks itself back off.

To me, I would be more worried about the engine roughness than the light. You seem to think it could be an engine misfire. Well, if it is due to something like a bad plug, it might result in raw gas being pulled into the exhaust. This can then enter the catalytic converter, be burned there, resulting in extremely high cat temperature - possibly to the point of burning up the catlyst bed, plugging the exhaust or (worst case) overheating the cat to the point it catches something aflame under the car.<p>Am I overreacting? Maybe - but I had one real bad experience. Had a '85 VW GTI that had a bad engine miss at about 6000 miles on a really cold winter day. Tried driving it home, but it died on a long upgrade. While sitting on the side of the road, a passing car slammed on his brakes, pulled over, and ran over to me, shouting "You've got a fire under your car!" . Jumped out, looked under it to see a cherry-red converter and some undercoating starting to smoulder. Had no extinguisher, no water around, couldn't even throw dirt on it (ground was rock solid from hard freeze but was no snow/ice on ground). Bottom line was that undercoating smouldered over to gas tank, melted a hole in the plastic tank, and car burned to the ground! Ugly lawsuit after that between me, my Perry Mason types, my insurance, all against VW!<p>Leson I learned - any car I drive with a catalytic converter - if it starts to misfire, it gets parked FAST!