Hey there, Let's say Google crawls a website and finds unreachable URLs because session variables were not established on the website and it was causing 500 Errors. So in the webmaster tools it shows over 1,000 unreachable URLs. If somebody fixes the problem, how long until takes away those errors and starts indexing the site properly? Sincerely, Travis Walters
There are two types of Google crawl: deep and shallow. Deep crawling, I believe, takes place every 3 months. Shallow crawling happens as soon as you update your site. You want Google to crawl your unreachable URLs fast, make a sitemap of those fixed URLs and submit them to Google.
The time it takes google to crawl your site varies. Isn't there a section in webmaster tools that tells you how often the googlebot crawls your pages? I remember seeing that before. And they crawl certain sites more often, especially sites that use google tools.
Some factors play roles in the timing factor and matter you have mentioned like how many backlinks your website has and how you regularly update your pages because an updated website with good links tends to have faster crawls and naturally the changes too would be reflected on Google Webmaster Tools more quickly.
i have same problems with twalters84. i also have submit my sitemap to Google webmaster tool. but Google still now crawel my site.