Front coil spring snapped while driving...
 

The front coil spring on my 190D broke this morning :( The lowest coil just snapped while going over a small dip in the road... I inspected the front suspension just 2 weeks ago and there was no sign of any problem.

The spring is still almost in its original position (see photos) - the bottom has shifted towards the engine by an inch or two. Fortunately, the car was still drivable after the spring snapped (although I don't intend to drive it now that I know what the problem is).

Do these springs need to be replaced in pairs (left/right) or can just the broken one be replaced?

I am hoping that a spring compressor can still be inserted up the center of the spring - the fact that it has shifted may cause problems getting the compressor in. Does anyone have any advice on how to tackle this job? I am afraid of the broken spring...

If you are going with new springs I would replace both. You can always beat it over with a hammer to get the compressor in.

By the rust on the inside edge of that crack I think its been broken for some time, it just needed some motivation to go all the way.

Yes, in pairs.

Thanks for the suggestions!

I replaced both front springs, using Swedish-made Lesjöfors springs. They had the MB part number stamped on them and fit perfectly; there was no change in vehicle height after the replacement.

I purchased the special spring compressor tool; it is a really well thought out tool and I cannot see how you could safely remove a spring without it. However, it does rely upon the spring sitting in its proper location in the car so that you can insert the tool from below (or above), and you have to grab as many coils as possible or you'll never get the spring in/out.