Stop
Never idle a car in a closed garage or enclosed space, even briefly, since exhaust fumes contain carbon monoxide and can build up to dangerous levels quickly.
Symptoms
- Exhaust odor noticeable while idling in the driveway or garage
- Smell less noticeable or absent while driving with windows down
- No dashboard warning lights necessarily
- Possible faint smell inside the car with the vents on recirculate
Likely causes
- CommonExhaust leak near the manifoldA leak close to the engine is more noticeable when there's no forward airflow to disperse it.
- CommonLoose or damaged exhaust jointA gap at a pipe connection lets fumes escape more when idling in place.
- PossibleIdling in an enclosed or low-airflow spaceA garage or space between buildings can let exhaust concentrate and drift back toward the car.
- PossibleCracked exhaust manifoldCracks often leak more noticeably at idle when the engine isn't under load.
What to do
- Never let the car idle in a closed garage, since exhaust fumes including carbon monoxide can build up quickly and are dangerous.
- With the car outside and idling, walk around and listen/smell for the leak location.
- Check visible exhaust joints and the manifold area for soot streaks that indicate a leak.
- Have a shop inspect the full exhaust system if you can't pinpoint the source.
- Have any confirmed leak repaired, especially since idling smells can indicate a leak that's also a risk if fumes get pulled into the cabin.
- Avoid extended idling near the car, in a garage, or near open windows until it's fixed.
Tools and parts
- Flashlight
Exhaust manifold gasketSearch: “exhaust manifold gasket for [year make model]”
When to call a pro
See a shop to find and repair the exact leak location, especially since a leak that's obvious at idle can also mean fumes are getting into the cabin.
Safety
Stop
Never idle a car in a closed garage or enclosed space, even briefly, since exhaust fumes contain carbon monoxide and can build up to dangerous levels quickly.