first thing I did today was t o check if my water pump is still working and I did the bleeding procedure and water pump was ok. Then I diagnosed if there is any error in the computer using DIS and found out there was one error (DME-intake side of VANOS stiff or mechanically faulty) but I am not sure if this error is related to the squealing problem. DIS did a test on my vanos and everything was on spec. I cleared the error and test drove it and for now the squeal is gone. I am not sure if it will come back again. It will be a wait and see. Also my coolant level was a bit low so I also added some coolant up to at least the minimum level since engine is cold.