Exhaust smell inside car 2004 Eclipse

My car has an exhaust smell coming into the car; seems to be from in front of the passenger side of the engine. Mechanic said it was from leaking valve cover gaskets, which have been replaced about a month ago. The smell is coming back and getting stronger. When I am in stop/go traffic, I have to open the windows. What else could this be caused by?

Is your exhaust sound getting louder? That would mean an exhaust system leak. Next time you get home, raise the hood and look for wisps of smoke rising from the engine. That would be oil leaking onto a hot surface, usually exhaust manifold or pipe.

where ever it comes from, you need to address it immediately! i hope your mechanic told you that.

has your car gotten louder? it could be exhaust manifold gasket or any component of your exhaust that is leaking.

leaking valve covers would seem more likely to cause a burnt oil smell in my opinion.

if it is exhaust leak, it could kill you

There is no change in engine sound or exhaust. I have looked under the hood. There is no smoke. The smell seems to be coming from in front of the passenger section.The engine is clean, there is no dripped or leaking oil - the oil level is constant.

There is still a possibility that unseen seepage of oil is causing the smell, but the OP needs to immediately find out if exhaust gas is actually getting into the passenger cabin.

I suggest that she go to Home Depot or Lowe’s, and purchase a battery-powered Carbon Monoxide Detector. Activate the detector, place it on the passenger seat, and drive for a few minutes with the windows closed. If the detector blasts a warning, that is your signal to immediately open the windows, turn on the vent fan, and drive directly to a muffler shop for evaluation of the entire exhaust system.

And, even if there is no CO inside the car, if your home doesn’t currently have a CO detector, this little exercise will allow you to add this vital device to your home after the experiment is over.

The exhaust pipes could be leaking. Oil burning has a very acrid smell. Antifreeze has a very sweet smell. Of course a gas leak will smell like gas. Exhaust has its own smell and could be coming from any point from where the headers bolt to the engine block to the tail pipe. You need to get it corrected ASAP. CO will first make you sleepy, pass out and then kill you.

"CO will first make you sleepy, pass out and then kill you."

That is true, but ongoing exposure to CO–even at levels too low make one sleepy–can lead to the death of brain cells. Like other slow processes, this is not usually apparent to somebody until it is too late, hence my suggestion to use a CO detector in the car immediately, so that exhaust leakage can be ruled out or ruled in.