when i'm driving, after about 20 minutes or so i will smell exhaust or it might even be the smell of burning oil. i notice it mostly when i am on the highway, but sometimes i smell it when i am the city as well. It seems like its coming from the heating/ac vents.

any idea what it could be, i have a 89 maxima SE

 

any noticable hissing under the car ? check the flex section on the y pipe they go bad after a while, that might be you exhaust smell...

 

uh-oh...it may be your exhaust studs. any sounds from the engine bay?

 

Do you have any oil leaks?

 

I have the same problem, lets hope thats its the flex pipe so a new Y pipe can be ordered !!!!

 

If you have your fan or vents set on fresh air it could be everyone else's exhaust. Or did you or someone else maybe spill oil on the valve cover after changing the oil or something? Maybe check under the car to see if it is leaking somewhere or do what the other's said and check your exhaust manifolds and flex pipe.

 

i had some screws loose on the valve cover and there was some leakage.

thanx everyone.