Bad Smell?

Hey guys, 1996 Ford Contour 2.0L 4cyl Zetec Engine 216.700kms, Automatic
My problem, well more of a nuisance, is every so often when i am out, i turn
on the heat, and this awful smell comes out, almost smells like burning coolant or something. I pop the hood and i can smell it under the hood, but i dont see any leaks and the coolant level remains constant. Any ideas what this could be guys? Not really an emergency or anything, its just annoying cuz it gets BAD and i have to turn my heat off and open my windows LOL...dont wanna have to do that come winter.
Btw...there is no particular scenario that causes this problem. It sometimes happens as soon as i turn the heat on, or sometimes after 30 mins, sometimes when engine is cold, sometimes when warm...
Ken
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Did you check the cabin air filter? http://www.cabinairfilters.net/cabin%20air%208046.htm

turn
but
what
sometimes
sometimes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.