Why don't 404 pages disappear immediately from search results?
Why Webmasters Stack Exchange recommends it
Webmasters Stack Exchange answerers link it when someone asks why removed or 404 pages are still indexed, as an official source that Google takes time to drop them.
Recommended by 1 people across 1 different months, 2012 to 2014.
What it is
A 2-minute Google Webmaster Help video in which a Google Search team member answers a viewer question about why URLs returning 404 stay in search results for a while instead of vanishing at once. It is a short, official explainer from Google Search Central (then Google Webmaster Help).
What people said
Recommends user37204 · 2014-03 · Webmasters Stack Exchange · on “Why doesn't Google remove my noindex and 404 pages?”
Sadly, you are taking all of the steps with the removal process. Google Webmasters also explains this issue with their YouTube video [this video] . It takes a good while for the actual removal process from all of Google and the search engine. Try to be patient now, and it will happen. Also, you have to remember, Google is indexing, re-indexing, and deleting records from their Search Engine all of the time at a massive rate already, but there is trillions upon trillions of sites that this needs to be done to and more links for indexing.
Cites bigblind · 2012-02 · Webmasters Stack Exchange · on “Does it make sense to return a 410 instead of 404 when some page has been permanently removed?”
Does it make sense to return a 410 instead of 404 when some page has been permanently removed? In this video [this video] , Matt Cutts says that Google treats them the same, but are there other reasons to implement a 410 (except for technical correctness)?
Cites Ilmari Karonen · 2012-02 · Webmasters Stack Exchange · on “sitemap and crawler”
Why do your URLs churn so much? You write: "[I]n webmaster tools I see a lot pages that were submitted months ago, currently deleted, and still in index even thought I retrieve 404 with noindex option." If you keep your pages up only for a month or two before deleting them, it's no wonder that Google can't keep up. In particular, keep in mind that Google will not immediately drop pages from their index when they get a 404 response [this video] — they'll wait a while, in case the error was temporary and the content comes back later. Besides updating your sitemap regularly to reflect new content, there are a few other things you could do that might help Google (and other search engines) keep up wit
Cites user37204 · 2014-03 · Webmasters Stack Exchange · on “How to permanently remove my blog post from Google's index?”
These all work to help the removal process, but Google WebMasters has a [this video] explaining that when a pages goes to 404 statues, and with how many links are being indexed, removed, modified, it is going to take time for them to remove the link permanently from the system.
Cites user37204 · 2014-04 · Webmasters Stack Exchange · on “Google still has record of my old site URL - what to do?”
Google Webmasters also explains why the URLs are still indexed with their YouTube video [this video] . It takes a good while for the actual removal process of the old links to happen. Also, you have to remember, Google is indexing, re-indexing, and deleting records from their Search Engine all of the time at a massive rate already, but there is trillions upon trillions of sites that this needs to be done to and more links for indexing. Just give it some time, but the links will be updated sooner or later. EDIT 1 You did all of the steps to fix the URLs indexed by Google. They just need to recrawl your website and index the links properly again. Also, did you submit a Sitemap of all of the new URL