i get a smell from my heating vents in the winter. no smell at all in the summer when a/c is on.

i am assuming it is an anti freeze smell on my heater core.

any thoughts on how I can fix this?

also is replacing a heater core a big job for a B6?

my mechanic seemed unsure when i described the problem

can you recommend a mechanic for this problem?..i want to fix it before the winter

thanks