i have a ole in my tire and it only releases air at high pressure. so i can’t find it. any ideas/support 
Go buy some SLIME at your LBS, or at any place that sells bike tubes, plop it in there(or buy a pre-SLIME’d tube) and the hole will seal itself. I have it in ALL my tire tubes, and never suffer from small puncture problems.
Check to see if it’s the valve core leaking. If it’s not a hole in the tube then it’s gotta be a leaky valve core. You can tighten the valve core with a special tool. The valve core is actually threaded in the stem.
If you remove the tube from the tire and inflate the tube till it’s oversized you will be able to find the hole. Put a mark on the tire where the valve was so you’ll be able to match up where the hole in the tube was with where that spot was in the tire. That way you can check the tire there to make sure there is nothing poking through the tire and still stuck in the tire.
inflate the tire then stick it under water so you can see where the hole is then mark it and depending on where it is(not at the valve) use a regular patch kit from a b*ke shop.
I didn’t read the rest of the replies already replied to this thread, so I’m probably repeating someone. but what I do, and everyone else does, is this:
take the tube out
pump it up
dunk the whole thing underwater
squeeze it
bubbles will come out where the hole is
take it out of the water, dry it, then patch it or do something to fix the hole.
thats what i’ve been doing but i still can’t find it.
The leak could be from the valve or around the area. How close did you look when you put it under water? Since you loose the air at high pressure that means that the hole could be super small and only a little air could come out making it hard to see.
My favorite tube hole finding technique involves putting a solution of dish soap and water all over the tube. Look for bubbles- there’s your hole. Also, if you pump the tube up really big and listen in a quiet place, you can usually hear the air coming out, even on a slow leak…