Not sure I need a root canal

[tomblack]

Hi
I recently went to a dentist to get one of my tooth filled. I don't have any pain but whenever I want to chew some food with it it feels like it's weak and a little sensitive.
I went and got some xrays and the dentist says that you need a root canal. i've asked 5 more dentists to see if it needs a root canal. only one of them said maybe you won't need it, we need to open it and see. he tried spraying cold air into it and tried tapping it with his instruments and I didn't feel any pain at all. I myself tried drinking hot and very cold water and experienced no pain!
I've added pictures of the tooth
why are they insisting on root canal?
what are your thoughts on this?

 

[tomblack]

umm...guys?

 

[drlolk]

umm...guys?

Hey dude, I have an opinion but first some questions.
the first x-ray image up there is that post filling or pre-filling?

 

[tomblack]

it's pre-filling

 

[drlolk]

in my opionin, this case was compromised from the beginning and most certainly I hope that the previous dentist tried his or her best to save this tooth. As an edodontist, I can tell you that tooth needs a root canal and I would also like to ask about the premolar next you the molar in question as I believe that it can also be compromised.

 

[drlolk]

p.s. your lesions seem to like a volcano or like a funnel shape they are small on the surface and them they just get wider and deeper as you go into the tooth. i wonder if that makes sense?

 

[tomblack]

thanks.
how come I don't have any pain on this tooth?
Can I just leave it as is until it becomes painful?