Heavy exhaust smell from A/C Solve For the past week and a half I have had a very heavy exhaust smell in my apartment, which seems to... (More) For the past week and a half I have had a very heavy exhaust smell in my apartment, which seems to be coming from the A/C vents. It leaves a bitter taste in my mouth and burns my eyes. This smell also gives me awful headaches. It is stronger right after the A/C kicks on, and right before it switches off. I have a combo Lennox A/C and furnace. I had a maintenance man come and he changed the filter, which was filthy (apartments responsibility, and I've been here two years and it has never been done, and I never thought to do it before). He looked and could not find a problem in the A/C, vents, no bird's nests, etc. The smell got worse. I called the gas company (no CO leaks supposedly) and they found what they called a 'small' gas leak, which was supposedly fixed by maintenance. The smell went away for almost a day after the repair took place. Now it comes and goes again with the cycling of the A/C. It does not smell like natural gas. It smells like auto exhaust. There was no idling auto outside anywhere when the smell started, and has been none since. We have no attached garage. Today I got so frustrated with the smell, I opened the furnace/A/C and hot water heater closet to vacuum out the lint and dust which was abundant. At that time, I noticed that there are three copper looking lines coming or going, from or to the A/C unit itself. All are leaking a clear oily substance. One has water condensation, yet all three are oozing oil at the connections. Is this normal? Because the maintenance man told me he checked EVERYTHING, yet as soon as I opened the closet door the leaking lines were right in front of my face. The maintenance man and the two gas company techs told me that a gas leak would not give me a headache, nor would it cause burning eyes and throat. Nobody would admit smelling any exhaust type smell. They have basically told me that I need to go see my doctor and find out why I am having 'phantom' smells. Today I went and got my neighbor to come smell my apartment. He said it smells like spent diesel fuel to him. So, while I have a witness to the smell, I can't convince maintenance that there is a problem. He is supposed to be certified in HVAC, but I am having doubts. How can I convince someone that there is a smell when they can't smell it themselves? Have you ever heard of such a thing from an A/C unit? Any advice will be so greatly appreciated! That you so much for your time. PS: I have an incredibly good sense of smell...always have.