GIVE ANSWERS - English

Hello  everybody.

I was making a " spot the mistake exercise and i have some doubts about 3 sentences. I can't guess where the mistakes are:

1. We were hot because we'd run. 

i thought the mistake was " because We had been running " but I am not sure.

2. It's time we go go.

I thought maybe the corretc answer was " it's time to go home"

3.  He climbed up the Mount Everst.

I presume the mistake is in the phrasal verb.

Someone could help me clarify these doubts. 

thank you and have a nice day.