I am currently have S40 which is getting a problem once I turn-ON the key before start the engine. Normally, I hear the noisy as emmmmmmmmmm for 2 or 3sec which is normal for S40 experience from the front left engine. Some owner or workshop explain this is for air-pump system.

Now the system has become abnormal noise which is hear as em..em..em..em..em...also for 2 or 3sec. But my car still can start & drive as usual. This is my question as below:

1. Will it to be spoil soon?
2. Why & what to be effected this happening?
3. This abnormal noise can be repair until return to the normal noise?
4. How much the cost if need to replacement?

I hope to get somebody to feedback on the further information, if there have this experience before.