Had my Audi a3 s line for a year now and had numerous issues. The latest one is like a juddering/pulling back mainly when accelerating. 

It started and then got the odd judder when been doing 70mph for a while. After a week the engine management light came on. Id taken it to the garage before this but was told they couldnt diagnose it. 

It came up that glow plugs needed replacing. I did this and the car was fine for a week and now its back to normal. 

No light just the juddering again. The garage said its like looking for a needle in a haystack so any help would be great.

Thanks

Sadly Jade, you have been misled about the glow plugs. They are only used to start the engine, and have no function once the engine has fired and is running. Your garage should know this even if the diagnostic scanner indicated a glow plug fault. I leave you to draw your own conclusions.

There are numerous possible causes for the juddering and the engine management light, and we are unlikely to find the right one purely from your written descriptions of the symptoms unless you have some technical knowledge and are ready to get your hands dirty. Is that possible?

However there is one question that might obviate a lot of investigation, even though it may sound irrelevant. How old is the battery?