A car’s transmission system is one of its most vital parts, and automatic systems use a pump to push transmission fluid through the valve body and into the gears. If that pump isn’t working properly, the transmission isn’t going to work properly either, and that can seriously impair the health of your vehicle. Automatic transmissions are both complex and expensive, so repairs and replacements really need to be avoided. You want to be able to know as quickly as possible whether there is something wrong with the pump, so here are four main issues to keep an eye out for.

1. Overheating

Unlike your engine, your transmission doesn’t have its own cooling system; instead, it relies entirely on transmission fluid in order to remain at a stable operating temperature. When the transmission pump begins to fail, that fluid will not be properly circulated and the system will begin to overheat. This may cause the overheating light on your dash to turn on, and you might notice a burning smell emanating from beneath the hood.

2. Loud and Jerky Shifting

Transmission fluid is cooled in order to maintain a steady temperature, but it also helps prevent overheating by lubricating all the gears in your transmission. If those gears are not properly lubricated, they won’t be able to work as smoothly. You may notice that your automatic system starts jerking or faltering when a shift is made, which will often be accompanied by a grinding noise.

3. Whirring Noise

Grinding isn’t the only noise that can reveal a problem with the pump. Your transmission pump is connected directly to the motor, and the motor needs to turn for the pump to operate efficiently. If any parts of the pump or the belts that connect it to the motor become worn or move out of alignment, you’re likely to hear an odd whirring sound when the car is running, even when you’re in neutral.

4. Transmission Fluid Leak

Your transmission pump propels fluid into the transmission system. If there are any cracks along its body, transmission fluid is going to leak out. This is unfortunately quite hard to spot just by looking at the ground beneath your vehicle, but you can always check the transmission fluid level manually if you suspect that something is wrong.

If you have reason to believe that your transmission pump isn’t working properly, make sure you take your vehicle to a professional as soon as possible.