What level of carbon monoxide (CO) is considered normal inside a car?

Julien-LaPointe
Thu, 31 Jan 2019 19:30:16 +0000
Maintenance/Repairs

My 2002 VW Passat was releasing fumes into the car and making me dizzy. I went to a VW dealership for the repair. It turned out to be oil and coolant leaking onto the exhaust. No exhaust leaks were found (checked by 2 mechanics).

The smell is gone, but I still feel dizzy from time to time. Given the health risk, I purchased a carbon monoxide detector (Fieldpiece SCM4 Carbon Monoxide Detector) to ensure exhaust fumes weren’t entering the car.

On a cold start, the detector reads a max. of 70 to 230 parts per million (ppm) for a short period of time (1 minute), then returns to 0ppm (screenshot: 2019 01 28 - Carbon Monoxide Reading.png).

Should I be concerned?

Given that car bodies are not completely sealed from the outdoors, I believe a small amount of CO for a very short period of time is normal, especially at startup in cold weather when gas isn’t burning efficiently. Is that correct? My CO detector just registered 18ppm for about 30 seconds in a 1-year-old BMW X1 in -10°C weather.

Thank you in advance to anyone willing / able to help!

15 posts - 7 participants