My 98 A6q idles very rough, and worst of all when I am idling along in traffic, at about 1200 rpm it almost vibrates. My mechanic has been working on the problem for a long time with no result (this is Mexico ... it's hard to find a good Audi tech). Most recently, he said the timing chain tensioner on the left side was not working (I guess this varies valve timing). So I invested the $700 on a new one ... it seems to have improved the situation a bit, but not fixed it.
Any ideas?

 

Look for vacuum leaks!

Do fuel system purge -but real one!

(If I may ask - what "TH" is the fun of having an Audi in Mexico?)

 

Could be motor mounts?

 

Thanks for the ideas.

The Audi is wonderful on the major Mexican highways. Most people take 4 hours to get to the beach in Manzanillo from here ... I do it in 3 and in comfort. The toll roads ("cuotas") are superb.

Mike

 

No .. they were replaced recently because we thought that may be the problem