Originally Posted by
ala_xfire
1. Yes, that coolant is fine.
2. No trickery that I am aware of.
Make sure you drain as well as you can, fill up with JUST distilled water, drive it awhile then drain again.
Fill up again with 50/50 mix your coolant and distilled water.
But like onehundred80 said, how are you sure it's not simply the tensioner or idler pulley making the noise.
If the water pump is OK, leave well enough alone and just change the coolant.
I would also make sure you test the final mixture to as close to a 50/50 as possible. If your in an area that def needs 50/50 qualities, you'll be glad you did. Good luck!