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.

 

1. Replace thermostat. (It fixed mine too)

2. Sounds like the compressor clutch from your description. Have you checked the R134a level lately? An easy check is to shine a bright light onto the A/C Drier viewport with the A/C on high. Facing the engine compartment it's on the driver's side behind and below the headlight. It's a small cylinder with 2 small metal lines bolted to the top. You will also notice a very small round window on top. You are looking for bubbles to indicate a low charge. No bubbles = full, big bubbles = slightly low, foam = very low. The viewport is thick so look deep into the cylinder for the bubbles. If present they will flow past the window with the liquid R134a.

3. The 1.9L S40 uses a wasted spark system like many other cars. (I had a 1987 Buick that used it). Notice that each coil has a corresponding plug wire to another cylinder? That's because each time the coil fires it causes a spark on 2 cylinders. However, only 1 cylinder is on the compression stroke and that is the cylinder that fires. The other is on the exhaust stroke and does not care if the spark plug fires. This simply saves money over 4 coils.

 

Thanks for the guidance.