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Q: Car cranks but won't start below 10 degrees F

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I have been having an issue starting my car after it has been sitting overnight in cold temperatures. It cranks but will not start. I replaced the battery and it did not fix the issue. If we try to jump the car, we can get it started after a lot of effort. After it starts, the check engine light came on and would blink sometimes. After letting the car sit for a while, the light turns off all together. I had codes pulled and had two P0300 codes, P0301, P0302, and P0304 come up. Knowing these are misfire codes, I took it to a mechanic. They were unable to get the car to misfire. They checked the coil packs, spark plugs, and fuel injectors and found nothing. I took the car home and had no issues. I drove it to and from work for the past 3 days (50 mile round trip) with no problem. Temperatures dropped again and when I went to start it this morning, and lo and behold, cranks and doesn't start! Any ideas????

My car has 120291 miles.
My car has an automatic transmission.

Hi there. When you start your car in the morning when it’s incredibly cold outside. 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. You may want to have the cold start injector replaced.

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Hello, thank you for writing in. The cold weather is a hard battle to win. There are a few things you can do to help prevent the cold from effecting the engine so much when it drops that low. However, there are likely no issues with the vehicle. You are going to need to do more to prepare for the weather instead. This would include finding a way to park your vehicle indoors, or getting a car cover to keep some of the moisture and cold out. The kind of oil you put in the engine may also make a difference. If the oil is really thick and cold then it will not lubricate and support the valves and lifters. Make sure you are using a thinner oil that will heat up quicker (but stay withing your manufacturer specifications). There are also after market heaters you can use on the system, but there need to be used carefully. For more help on starting the vehicle in cold weather, contact our service department.

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