I sit in my car all night for work, and about a year and a half ago, I started getting really dizzy and nauseous about 6 hours into my shift. This was during the winter, and I would start the car up every couple of hours and let it run for a minute to warm up the cabin. About the same time, I started noticing an exhaust leak that got worse and worse and louder and louder. I went to the doctor, who was completely worthless, but I eventually figured out on my own that I was getting carbon monoxide poisoning. I got the flex pipe replaced and the symptoms went away. Recently, I drove with the air conditioner on, and I got the same symptoms. When I start the car, I can smell what smells like gasoline. I took it to the muffler shop, and they said that the flex pipe wasn't leaking, but the valve cover was and the oil on the manifold was causing the fumes. Is this possible? Has this happened to anybody else? Where are the air intakes located? I have been driving with the windows down to keep from getting sick for a couple of months. It's the middle of the summer, and I would prefer to be able to use my air conditioning.

 

If the valve cover is leaking, put a new gasket on it.

Also have someone look at the exhaust manifold to head gasket. The torque specification on those bolts is very low, and they can get loose, causing an exhaust leak.

 

A fuel smell can also indicate a vapour line leak , have a look at the fuel/ vapour line under the HHR just in front of the driver’s side rear tire!

 

There is a gasket that goes between the exhaust manifold and the connecting pipe, it is a triangle shaped flange gasket. This gasket may have blown out. It is easily accessible under the car and requires removing 3 bolts. That is where I would start.
You can feel around the flange from under the hood with the engine running to see if you can feel an exhaust leak.

 

Or look for dark spot marks from the exhaust leak.


Have a look down here , a mirror might help