Now that I have completed summer school and got a high enough grade to get back in engineering(2nd year), why does my SOLAR account not let me choose and subjects for my 2nd year.
Also why does the grade report not get updated?
Thanks in advance guys...

The grade reports are not fully out, around end of august. Also, acceptance into an engineering discipline is only based on your year 1 (no summer) marks. Say your GPA was a 3.7 and after summer it is 4.5, the faculties will only look at the 3.7. Also remember that your GPA must be above 4.0 to stay in the program else you will be under academic probation/reinstatement (I don't think you can reinstate twice). You have to be accepted into a program to choose marks. Email Sally Williams about it, she will email you back when you get re accepted.
http://www.eng.mcmaster.ca/about/peopleassocdean.html

May I ask what courses you found difficult? That got you under the 4

I sucked at visualizations so I did poorly on eng 1c03. I sucked at physics so I did poorly on that too.

The way they calculate your gpa after summer school is a bit confusing. They don't take the highest mark and drop the lowest, they also don't add the two marks and divide them by 2. They actually use both marks in calculating your gpa to get into second year.

So let's say you took a full load in first year, and only repeated 2 courses that you got 1 in during first year. If you repeated both courses and got a 7 in both, they will divide your overall average by:
37+3+3 = 43 units and not 37.

As Leeoku said, the grade report page will not show you your marks until late August. All of your marks should be on the degree audit.

I think you should talk to Sally in person asap, she will help you out with everything! Good luck and congratulations on getting high grades