Error 404 - Does Google Penalise For It?

[Alon]

Does google penalise for significant number of 404 errors.

We had our pages automated to 301 when we deleted pages. Today , I checked webmaster and noticed 165 warnings of 404.

If our site has 301 how does google then picks this up?

we now designed 404 unique page that shows users site map search box and links to main site. Is it advisable to have no follow index on 404 pages?

Is it advisable to remove old URLs using webasters tool?

Thank you guys

[lucy24]

We had our pages automated to 301 when we deleted pages.

301 to where? The front page? Google calls that a "soft 404" and they absolutely hate them.

That being said... wmt lists all the 404s and 410s that they ever find. It doesn't necessarily mean you did anything wrong. "Yes, thank you, I know it's gone, I deleted it myself." It's just for your information.

we now designed 404 unique page that shows users site map search box and links to main site.

Good. Humans see the page. Robots see the 404.