I have a 2000 A4 Quattro, 1.8L Turbo, and I have had a peculiar ongoing issue... About 6 months ago, the engine light was flashing and the car was "chugging", so I took it in and had all 4 coils replaced. The car worked great for about four weeks. The issue recurred, so I took it back in, and error codes showed a potential vacuum issue, which the mechanic (who specializes in BMW) wasn't comfortable with working with, so I took it to the local VW/Audi place about a week later (I was told it wouldn't be a problem driving it as long as I took it easy), the engine light had gone off the day before and car was working alright. It had been intermittent during the week. The Audi people could find absolutely nothing wrong with the car outside of some error codes for the stereo. The car ran beautifully for the next two or so months. Just the other day, the engine light came back on, the car is "chugging" again, and on a whim I checked the oil. It was very, very low. Of course I topped off immediately, which made no change to the engine light, but I am perplexed at how this situation comes and goes, and could effect the oil levels so much in such a short period of time. Any ideas? As far as the engine light, I've had the car for just under a year, was told that it was perfectly maintained prior (which I don't really trust), and I have a suspicion that the plugs need to be replaced, as the shop that replaced the coils did not check the plugs. Any ideas that would cause such strange and intermittent symptoms? Any help would be greatly appreciated!

 

Apparently, it seems to be the oxygen sensors. Hope this helps someone else, as no one had any input. This is close to an $800 repair outside of the dealership.

 

More to the story... The oxygen sensors don't quite make sense... They do make sense with the vacuum hoses to some extent, but it seems it would be a constant issue, not intermittent. Also, why the large amounts of oil consumption suddenly? The "chugging" and misfires are worse in cold weather, rain, and stop and go traffic. Freeway driving usually stops the misfires. Anyone have any better ideas?

 

I'm sure need more details, but I doubt I can help much...is it automatic or stick? When you say "very low" on oil, how much did you have to put in to bring it to full?

I had chck engine lights come and go periodically for a long while now it seems...

Right after they replaced the cam follower, then my transmission blew up. They never did figure that one out, and now they got one in there with the same symptoms I used to have

 

Thanks, Slack Jaw... It's a stick shift. I had to add two quarts, which seemed like not enough compared to how low it was registering, but filled to the top of where it should be. It was mentioned to me that it could be the crank case ventilation system, but even then it should be constant, and not an intermittent issue. This is getting to be a bigger and bigger mystery every day. Any help at all would be appreciated. Thanks!

 

that kind of diagnosis is way out of my league...good luck though

 

Thank you! Engine light is off again and it's running like a dream. This keeps me scratching my head...