Ask the Beaverton Car Guy: Cars and cold weather

Ask the Beaverton Car Guy: Cars and cold weather

Why won’t my car start when it’s cold?

Hello Loyal Beaverton readers,

Thank You to all of you who have called or emailed over the last few weeks. I appreciate the questions and feedback.

Recently with the colder weather, we have had a number of calls regarding cars being more difficult to start. I realize it has warmed up a bit, however when the exterior temperature is lower in the windier/cooler months these are some things to consider.

Cold winter mornings are one of the worst times to have problems getting your car started. Unfortunately, those same cold mornings are also the times when you’re most likely to have trouble. Here are some tips to help you get your car going on a cold day – and to help you avoid car trouble in the first place.

5 reasons cars don’t like getting cold

In order to know what should be done to prevent cold-weather starting issues, it’s helpful to understand exactly why cold weather makes it harder to start cars. There are four reasons, three of them common to most cars and a fourth that affects older models:

Reason 1: Batteries hate the cold

Cold weather and car batteries simply don’t mix well. Every chemical battery, including the one in your car, produces less current (basically, electrical power) when it’s cold — sometimes a lot less.

Reason 2: Engine oil doesn’t like cold much either

In cold weather, engine oil becomes thicker and doesn’t flow as well, so moving the engine parts through it is harder. That means that your battery, which has been weakened by the cold, actually has to do more to get the engine moving so it can start.

Reason 3: Cold weather can cause fuel problems

If there’s any water in the fuel lines (there shouldn’t be, but it happens), sub-zero temperatures can cause that water to freeze, blocking the flow of fuel. This is most common in the fuel lines, which are thin and easily blocked by ice. A car with frozen fuel lines may turn over just fine, but it won’t run on its own.

Diesel drivers take note: diesel fuel can “gel” in cold weather, meaning it flows more slowly because of the cold, and making it harder to deliver to the engine on start-up.

Reason 4: Older cars can have carburetor issues

Cars built before the mid-1980s usually used carburetors to mix small amounts of fuel with the air in the engine. Carburetors are very delicate instruments that often don’t work well in the cold, particularly because tiny nozzles called jets get clogged with ice or because fuel didn’t evaporate well in them. This problem doesn’t affect cars that don’t have carburetors, so if yours was built in the last 20 years, you don’t need to worry about this. However, drivers of older or classic cars will need to be mindful that cold weather can cause carburetor issues.

A note on car batteries

Remember people, the car battery is only designed to start the car’s engine. It is not designed to run the stereo, or dome lights for extended periods of time. If you plan to spend more than just a few minutes in the car, it is wise to start the engine so that the vehicles charging system provides the power to our accessories, instead of the vehicle’s battery.

Thank You all again for reading.

If we can help with the purchase or with the sale of a vehicle please keep us in mind. I guarantee you will not get a better deal than we can help you get. We can be reached by telephone (503) 930-1493 or at By Larry “The Car Guy“ Ferguson