hi, my 7 year old hermann tortoise keeps on opening his mouth very wide, he holds still for 4 seconds then closes again, hes done this a number of times this afternoon and keeps making funny noises. He is normal in himself, eating and very on form! is this normal?

Do you mean as in yawing? If so this is normal. Making noises is not though, so it mgiht be that he has something stuck in his mouth - could you take a look?