Questions and Answers

Cold Weather Effects

Q. Hi Vince, I'm Back again!

• 1994 Camaro
• 3.4l
• Manual Trans
• 100,000 miles

We are having an exceptionally cold winter in the Northeast. My sons Camaro starts every morning, no problem. It sits outside all the time. Because of this I have been lulled into complacency.

Last Saturday, we shoveled out from yet another storm. I had my son start the Camaro and let it sit to warm up and melt off the layer of ice on the windows. As it idled, I noticed that it was not as smooth as it was in the summer. The idle improved as the car warmed but never really achieved that purrrrrrrrr.

Tell me about the impact of cold weather on fuel, air intake, combustion, sensors, oil, etc. Should I expect perfection in the cold? Should I treat the fuel in any way?

Don

A. Welcome back Don!! I'm always happy to see a repeat customer. I'm glad the car is doing so well for your son.

95% of problems in cold weather are starting related. Usually flooding because the fuel is too cold to atomize properly or batteries are too weak to crank or supply full voltage to the ignition system.

In theory, once the engine reaches operating temperature, it should run the same regardless of outside temperature. But I have found that this is not necessarily true. Now I'd be hard pressed to back this up with facts and figures, but I believe a lot of it has to do with the general lower operating temperature of the engine.

Engines are designed to operate within a specified temperature range. In winter the engine does run cooler. You have frigid air coming into the engine through the air intake and through the radiator. 20 degree air is going to absorb a lot more heat than 80 degree air so more heat is drawn out of the engine. I have noticed this in my 1987 Nissan Van. In the summer the temperature gauge sits right in the middle and in the winter it barely goes above the first mark, despite putting in a 195 degree thermostat. And I notice it more so in my diesel Mercedes where I have to completely block the radiator to get it up to 80c (about 170).

You might try putting in a hotter thermostat in the winter and going back to a cooler on in the summer. I do that with my Van. In the winter it get's a 195 and in the summer it gets a 170. As far as treating the fuel, about all I would do is add a bottle of dry gas in the tank when you fill up. Read the bottle to see how many gallons it treats, but I always dump two bottles in my tank. If Pennsylvania is using an ethanol blended gas formula, then this is not necessary since dry gas is ethanol. Also, if you're not already, I would use a name brand fuel such as Mobil, Shell or Hess. If you get gas at a no-name station you don't know what you're getting. They usually buy by price so you may get one brand this week and something else next week.