Exhaust smell inside the cabin

Symptoms

• Exhaust or gasoline-exhaust smell noticeable inside the car while driving, especially with windows up
• Possible headache, dizziness, drowsiness, or nausea during longer drives
• Smell may be worse at idle, in traffic, or with the rear hatch/window open on an SUV or hatchback
• No obvious source visible without checking underneath

Likely causes

• CommonExhaust system leak (cracked pipe, bad muffler, damaged gasket)A leak upstream of the rear tailpipe can let fumes escape near the underside of the car, where they can be drawn into the cabin through the fresh-air intake or gaps in the floor.
• CommonRear hatch/tailgate seal issue on SUVs/hatchbacks/wagonsA perfect vacuum effect at certain speeds combined with a worn seal can pull exhaust into the cabin through the rear of these body styles.
• PossibleRusted-through floor pan or trunk floorSevere corrosion can create a direct path for exhaust fumes to enter the cabin from underneath.
• PossibleExhaust manifold or gasket leak near the engineA leak closer to the engine can be drawn in through the fresh-air intake at the base of the windshield.

What to do

1. Open windows immediately for fresh air and switch the climate control to bring in outside air (not recirculation) or off if you suspect exhaust is entering.
2. Have someone start the car and listen underneath for a hissing, rasping, or louder-than-normal exhaust note that could indicate a leak.
3. Visually inspect the exhaust system from the engine to the tailpipe for rust-through, holes, or disconnected sections.
4. On SUVs/hatchbacks, check the rear hatch seal for gaps or damage, especially if the smell is worse with the rear window cracked or the hatch not fully latched.
5. Do not continue driving with windows closed and recirculation on if you strongly suspect exhaust intrusion, and see a mechanic as soon as possible.
6. Consider having a carbon monoxide detector for the car if you drive an older vehicle prone to this issue, as an extra safety measure.

Tools and parts

When to call a pro

See a mechanic immediately for any suspected exhaust smell inside the cabin; this is a carbon monoxide safety issue, not just a nuisance smell.

Safety