Greetings all, from the Audifans group!(die hard Audi fan here, the "patient" is the parental unit's 960 wagon.) The patient in question is a '95 960 with the inline-6 engine, automatic tranny; 70k miles or so. Mobil 1 synthetic used since about 40-50k.

Basically, at idle(looks to be about 900-ish, just guessing; tach is useless), the engine seems to be misfiring to the point that the whole car will shake regardless of the gear(P, N, D, etc)

Odd aspects:

-car otherwise performs flawlessly; tap the gas, car's great off the line; acceleration is smooth; no problems cruising; etc.

-idle, though rather violent, is a somewhat constant speed(tach needle steady as a rock)

-soon as you raise the idle even slightly(or idle is raised because car is in drive and in motion, coasting to a stop) the shaking dissappears

Checked:

-airbox is properly clamped shut, all hoses passed the squeeze test, clamps are tight

-connectors on idle stabilizer valve, MAF sensor checked, seemed secure

-codes pulled(111, everything fine)

Car has been serviced regularly by Boston Volvo Village.

I recently snuck a bottle of techron(constant use formula, same stuff I use in my Audi) into a full tank of gas a couple weeks ago; problem surfaced a week ago, so I doubt the two are unrelated.

Any suggestions?

Brett