If I release, sell or give my life estate to my child, can they then obtain a loan on house?

You don't provide enough information to answer the question here, and this isn't a forum that is suited to answering a specific, facts-based question like the one you're asking. In order to have someone actually able to tell you what might be possible, you really need to have an attorney review the documents that created the life estate, so that the attorney knows whether an restrictions apply to it, who the remainder beneficiaries are, and other facts. In general, IF you hold a life estate, you may be able to let your child have the use of the property during your lifetime, but your child still may not be able to take out a loan on the house unless the child is the only remainder beneficiary. But these general statements are subject to many possible variables, and without seeing the actual document that created the life estate it's not possible to tell you how yours is set up. Best wishes to you.