Getting into your car and hearing a loud “pop” when you turn it on can be rather scary. However, a backfiring car could also completely lose power, which can be even more concerning. As it turns out, there’s a few reasons as to why your car might experience a backfire…
Backfiring Car: Potential Problems
Poor fuel-air ratio
The way modern combustion engines work is to basically harness the power of small, controlled explosions to generate power and move your car. So, when you’re dealing with a backfiring car, what’s happening is that one of those explosions occurred outside of the fuel cylinder. Hence the loud pop and even the flames which can come out of the exhaust!
It could be that these backfires are due to a bad fuel-air ratio. When an engine is “running rich”, there’s too much fuel and not enough air, which causes the exhaust valve to open while the explosion is occurring. If it’s “running lean”, then there’s too much air and too little fuel, which delays the process entirely. In either case, you’ll want a professional to inspect your engine to fix the problem.
Misfiring spark plugs
A backfiring car could also be due to misfiring spark plugs. It could be that your spark plugs fire either out of time, or don’t fire at all. There could also be issues with the wiring, or damaged distributor caps which deliver the charge to the wrong plug at the wrong time.
Now, usually spark plug-related issues are more common in older cars rather than newer ones. Still, that doesn’t mean new cars can’t experience these issues. Carbon buildup, rust, and general wear over time can lead to issues with spark plugs, and in turn, cause backfires.
Timing is crucial for any combustion engine. If any part of the process is out of time, then it can result in a backfiring car. For instance, issues with timing can lead to valves opening or closing at the wrong time, or sparks arriving too early or too late. Whenever the engine isn’t able to properly compress, ignite, and contain those explosions, then you can experience a backfire.
Much like with spark plugs, timing issues occur more often in older vehicles. These cars have to make use of timing belts and catalytic converters, which increases the chances of something going wrong if those parts fail. Modern cars make use of computer-controlled timing, making them more reliable.