Can anyone speculate as to why I momentarily lose
forward motion (as in neutral) while accelerating or high speed cruising--No apparent engine hesitation or rev. No apparent gear shifting problems or shift out of gear. The loss is appx. 1 sec at a time, barely discernable and occurs once or twice per mile. 89 200TQ 5-speed manual, 155k. Could this actually be loss of forward motion or something else that feels like that loss? Search function is down so I couldn't check archives. Thanks for any input.

 

I'm just guessing, but if it only does at high RPM or at high speeds, and only for a second at a time you may not notice a change in the tach, so it could be as simple as a loose wire somewhere. Does it do it at all engine temps? Does it matter what RPM you're at?

 

Since it happens without warning (and my kids insist I watch the road and not the tach--sheesh, they're no fun), I haven't been able to "catch it in the act." It does seem to do it at higher rpms. I've been warming the car before driving since it's been so cold here and I have to travel up a mountain before the car has a chance to warm up enroute. I don't know whether it would do it when the engine is cold. I do have the Bentley manuals but they haven't been much help at troubleshooting. (I got them to keep in the car when I have to take it to a non-Audi garage for repairs--Just in case)

 

...the ignition switch. The A4 did that to me one day and I found out it didn't start one day either and I'm suspecting the ignition switch. Of course this started right after the warranty expired! Hope it's nothing serious.

 

Starting with the simple things. A little bit different, but on race engines I've had in the past, I've had spark plugs and wires do the same thing at high RPM's. Are your's in good shape? It sounds like it could possibly be anything - fuel, ignition (electrical), or engine related. Hopefully it's something easy and not so expensive. Is there any way you can see if it does it when the engine isn't as warm as normal? I've had ignition modules (again different engines, but same idea) miss when they got hot.

 

Could your clutch be slipping or is it different feeling than that?

 

It does feel like momentary clutch slip although I've had no apparent clutch problem. An ignition module was installed a few months ago (part from all-audi that was guaranteed to work upon installation--It did). At first I thought it might be fuel/line/pump related but thought if that were the case, it would probably have other symptoms. An electrical defect sounds plausible. I did have a similar problem when the module went out--the car lost forward motion (with the engine running smoothly/no rev), then shut off in a blue smoke. It re-started and ran OK after that but had to be towed a couple weeks later after a no-start and the (non-Audi) mechanic then replaced the module. The car stalled again a couple weeks ago under the same conditions. Had it towed again to an experienced Audi mechanic--He started it the next day without trouble and drove it for several days and couldn't duplicate the stall condition. I had him change the timing belt and drive belt while it was there. He didn't notice this condition or would have mentioned it. It either didn't do it, or he didn't catch it in its subtlty. This is the first time I have noticed this motion loss independently of having the car stall/die and assumed this time the condition is a problem in itself. The other times, I just assumed it was an Audi quirk (there are some of those, eh?) that the car does this when it dies of another problem.
Yikes--Here I am, having spent $2,000.+ in misc. repairs since I bought the car July 1st and may still be dealing with the same problem--That's a scary thought--Each time I fork over the big cash, I think, OK, this will be it--This baby's gonna run forever now (or at least until Spring)

 

Just like my problem. When you find out what it is let me know.