Black smoke from front grill

The first thing I would do is a quick visual inspection for any oil or fluid leaks near the area where you are seeing the smoke. After confirming that there is nothing leaking onto an accessory drive belt or the exhaust manifold I would check the fans. With the engine cold you need to gain access to the fan blades and turn them slowly with your hands to verify that the spin freely and most importantly smoothly. If you feel any roughness, or if the fans are binding up or sticking at any point in rotation, there is your problem. You say that it smells like oil or grease, but most oil burning will give you a grey smoke. The black smoke sounds like electrical smoke which points towards a fan problem. Let me know if I can be of any more help.

Yes I have checked the leaks and left a cardboard under the car overnight. There is no leak. Main fan is working freely. I try to move auxiliary fan and it did move freely, however I didnt try the whole circle. I will try that and come back to you.

Regards

I will do a little more research as well. When you are checking the fans, do a quick visual and make sure that the wiring in that area looks ok. There is always the possibility of something not fan related. Let me know what you find.