Q: Car won't start in cold weather.

asked by on January 08, 2017

Car wouldn't start in 20 deg weather, it would crank for a while but not actually start. I got a ride to work and when I had gotten back, the weather had heated up to about 45 deg, however the same issue occurred. I tested the battery and it was at about 12V, it is a couple months old. Is this a cold battery issue or something else? The car was fine before the temp dropped.

My car has 165000 miles.
My car has an automatic transmission.

Hi There, When you start your car in the morning and turn the key to on, the coolant temperature sensor immediately reads the temperature of the coolant and relays this to the computer indicating that the coolant is cold. The computer then knows at this point that it needs to enrich (add more fuel) the air/fuel mixture at startup due to the change in air density. When you start the car, you will notice that it idles high for a period of time until the engine warms up. This is the enrichment cold start process. This is done with what is called a cold start injector which injects more fuel into the motor until the engine reaches a specific operating temperature. The computer simply feeds a little extra gas through the fuel injectors to start the engine and then maintains a certain amount of fuel supply to the motor until it is warm. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle and diagnose your cold start issue.

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