: 3440x4608 px
: July 5, 2018
Of course, in modern cars, there are battery charge indicators (in the same panel as the speedometer, fuel gauge and temperature gauge). Using these indicators, you can be able to know when your battery is developing problems, like when it is losing charge too quick, even without opening your car's bonnet. Naturally, these indicators only work for as long as the battery is at least 'basically functioning;' for it is the very same battery that powers them.
An old oxygen sensor (say, 90,000 miles or more) may still work well enough that it doesn’t trigger the check engine light but could still hurt fuel economy. Engine performance can also be reduced by more serious internal problems, such as valves that don’t seat properly or worn piston rings, or by restrictions in the exhaust system. Because the same symptoms can suggest different problems, and there are often several possible causes and cures, it’s better to consult a professional mechanic than to try to be one if you have neither the experience nor the right equipment to diagnose drivability problems. In short, rather than ask for a tune-up, tell a mechanic what you’re experiencing and ask him or her to find the cause.