One of my good friends just bought a 2003 S40 (1.9 Turbo) I want to help him out in starting off on the right track, and have a couple of questions.

1. The check engine light is putting out a code 128 which indicates lower than normal coolant, but the gauge stays steady near the middle, and the engine runs fine. The "burp" bottle is up to the normal level with coolant.
Any ideas ???

2. When ever you turn on the A/C there is a very distinct clicking noise that sounds like it's coming from right behind the glove box. It clicks about 10-12 times and then stops. The A/C works fine.
Any ideas ???

3. We're going to change the plugs in a day or so. Is there any reason why only two of the cylinders has a coil on top of the plug ??

Any help is greatly appreciated.