I recently performed a cylinder leakdown test searching for a cause for oil loss. On 5/6 cylinders, I pumped it up to 90 psi on the left gauge and the right gauge was between 75-80. Only 1/6 wouldn't go past 65. I put my hand on the intake for that cylinder on the plenum and didn't notice and leaks, then put my hand on the exhaust pipe and there was maybe a very low flow. The air may have been going past the cylinder rings and into the crankcase but I'm not sure how to check that.
How bad is a 30% leak, especially if it's on the exhaust side ?