1996 LXI with the 3.8 go out and start it, starts fine, let it warm up, go back out and there is a fairly strong, distinct burning/melting smell inside the cabin...you can go out and smell around hood/fenders/motor and cannot smell it...dirve about 10 miles to town and still smell it...don't see anything burning or melting though yet...was thinking maybe converter?....vehicle doesn't overheat, still seems to run fairly good, does have 140,000 miles...any known issues that causes this?