| If your roof vents get clogged you will have drainage issues like sinks not draining, toilets flushing slowly etc,etc. Does this smell seem like a cars exhaust or is it something else ? Post back and try to be a little more specific if you can I know smells can be tricky but they are even worse for us since we cant smell them at all. Are these odors making you feel bad or just bothersome odors ? If you feel this is affecting your health might be best to call in a contractor to have a look or a sniff(lol) and see what they tell you. Either way keep us posted and we will try to help if we can . Oh one more thing do you have any gas appliances , Fire places anything else. As mentioned in the previous post if it smells like car exhaust do you leave a car idling in a garage or on a carport even near a package unit ac system where the whole unit is outside any of these can bring the smell into your home. GOOD LUCK ,AC |