Last winter, my car sporadically stopped while I was driving slowly or while I was standing still. I usually turned the engine off and restarted it right away without a problem. It happened a few times and then it stopped. This winter, it began again - frequently. I realize now that it only happens during the cold months. What is wrong with my car and what should I do?
What brand and model car? What engine and transmission do you have? How many miles on it, and what is the year of manufacture?
… and did the CEL (Check Engine Light) come on? If so, what code (Like P0123)
These symptoms can be caused by too lean of a fuel/air mixture. A vacuum hose leak or vacuum controlled device leak is a common cause. Easy for a mechanic to check, and probably one of the first things to try beyond reading any codes associated with a check engine light.
Thank you for your responses. It is a Chevy, Lumina 1997. The Engine light frequently goes on and off. I don’t know the code but a mechanic said there must be air coming in somewhere. I wasn’t sure what that meant but he said I shouldn’t fix it. He said the car can operate fine the way it is.
I am a bit ignorant when it comes to cars - can you elaberate on what is “too lean of a fuel/air mixture,” as well as what does a “vacuum hose leak or vacuum control device leak” mean?
And why is it only hapenning during the cold months?
That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
In the cold, things tend to shrink down a little bit; When things warm up, they expand
Likely, what’s happened is your rubber seals are showing their age(15 years old) and don’t fit right when it gets colder and they shrink a bit.
Re: Lean fuel/air mixture
For the car to run smoothly, the fuel/air ratio being burned in the cylinders has to be correct. Too low, car won’t run right. Too high, car won’t run right. The car’s engine computer (ECM) does this using the O2 exhaust sensor(s) in a feedback loop to keep the fuel/air ratio just right for the engine operating condition. For the computer to do its job correctly, the computer must know the exact amount of air entering the engine. It does this with the mass airflow sensor (MAF), which meters (measures) the air as it is sucked into the engine. But if there is additional air getting inside the engine which isn’t measured by the MAF, that confuses the computer and causes the wrong fuel/air ratio in the cylinders , usually the result as you might expect is too much air and too little fuel when unmetered air enters the engine. Too low of a fuel/air ratio for the car to run smoothly in other words. This type of mixture is called “lean”. With a “lean” mixture, it is very temperature sensitive, it might run ok on a warm day when the engine coolant is warm, but most decidely won’t run well at all on a cold day, especially when the engine coolant is cold. It’s like if you were trying to start a fire with a match. You have plenty of air, but not much fuel, right? And just as above, it would be harder to start the fire with a match on a cold day when the wood was cold, than on a hot day when the wood was hot.
Re: Vacuum leaks
When the engine runs, it draws air in through the air filter by the force of the vacuum produced by the pistons moving downward in the cylinders. Similar to drinking a soda with a straw, the coca cola moves by the force of the vacuum, against gravity, up the straw. This vaccuum force is used not only to draw air into the engine, the engine designers said “hey, this is a force that is there for the using” and they decided to use it to control various gadgets on the car. Like if you have power brakes, the engine vaccuum force is used to produce a greater braking force than you could apply with just your foot on the brake pedal. But these vacuum controlled gadgets – such as the power brake booster – they all have use a rubber-like membrane to transmit the vacuum force from the engine to the gadget. And if the rubber springs a leak, then unmetered air can leak into the engine through that device. Likewise, if the vacuum hose going from the engine to the device springs a leak.
Cold weather makes for a more challenging enviornment for any car motor. A motor that runs fine in the summer can be a bear in the cold. First, make sure the motor has good spark plugs, and if equipped a new distributor cap, rotor, and plug wires. A '97 Lumina I believe has 3 coils and does have spark plug wires. Have you had new spark plugs put in the car? How long ago? New Plug wires? How 'bout a new air filter?
If the check engine light is on, and you haven’t done much to maintain the motor then stalling in cold weather isn’t a surprise. I think your car is trying to get your attention and could need some basic maintenance.