I had this problem on my old MTB. Every time I put some good pressure on the pedals, the clicking/squeeking noise started.
If you're completely sure it's not the pedals, then maybe fixing that crankbolt and getting a good one will fix it? Thinking that crank might be just sliiiiightly loose, so it moves abit when pressure's applied and makes the noise.
I had this problem on my old MTB. Every time I put some good pressure on the pedals, the clicking/squeeking noise started.
If you're completely sure it's not the pedals, then maybe fixing that crankbolt and getting a good one will fix it? Thinking that crank might be just sliiiiightly loose, so it moves abit when pressure's applied and makes the noise.