On the form 8938, should I report my foreign bank saving accounts without interest last year? My saving account only generates interest when closed and it was not the case last year

For both the FBAR and Form 8938, you must report ALL your foreign bank accounts if you meet the requirements to file.  The filing requirements are based on the total value of your foreign accounts and assets, not on whether any interest is earned in the accounts. 

https://www.irs.gov/businesses/comparison-of-form-8938-and-fbar-requirements

Thanks, but where do you see in this document we have to report "ALL your foreign bank accounts" even if these don't have interest?

If I have to file Form 8938, am I required to report all of my specified foreign financial assets regardless of whether the assets have a de miminis maximum value during the tax year?

If you meet the applicable reporting threshold, you must report all of your specified foreign financial assets, including the specified foreign financial assets that have a de minimis maximum value during the tax year.  For exceptions to reporting, see Exceptions to Reporting on page 6 of the instructions for Form 8938.
<a rel="nofollow" target="_blank" href="https://www.irs.gov/businesses/corporations/basic-questions-and-answers-on-form-8938#OverviewQ1">https://www.irs.gov/businesses/corporations/basic-questions-and-answers-on-form-8938#OverviewQ1</a>
<a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-pdf/i8938.pdf">https://www.irs.gov/pub/irs-pdf/i8938.pdf</a>

"If you are required to file Form 8938,
you must report the specified foreign
financial assets in which you have an
interest even if none of the assets
affects your tax liability for the year." --> It does not say "ALL".