For the last few months, I've had an annoying problem with my 2003 Liberty. If I'm driving the car with the blower on (i.e. when it's cold out), whenever I stop the car and am idling, I get a very strong exhaust smell coming in through the vents. If I turn the fan off, the smell goes away. At first I figured it was due to being behind other vehicles, but now I've noticed that it does it all the time, even when there's nobody else around.
I brought the jeep into a shop a couple of weeks ago to deal with a separate CEL issue (evap leak - fixed by replacing gas cap) and I asked the mechanic to look for an exhaust leak. He said he didn't see any readily apparent problems with the exhaust line.
I'd like to deal with this because it's not very pleasant to inhale exhaust fumes through the vents. I intend to take it back in - but is there anything I can tell him (i.e. like, a particular part of the exhaust system to inspect more carefully) that will help him solve the problem?
Any input would be greatly appreciated.