The transmission is one of the most important parts of your car's engine. To keep it running properly, check the engine's fluid levels regularly, keep the fluids at the correct level and change them when needed. If your transmission fluid has a foamy appearance, it may indicate a few possible problems with your engine.
Foamy transmission fluid may result from improper automatic transmission fluid (ATF) level. If the ATF level has dropped too low, the transmission pump will suck air into the ATF. This will cause air bubbles in the fluid, making it appear foamy. Too much ATF may also cause foamy fluid. These issues show why you should regularly check your ATF fluids and keep it at a proper level.
If you put the wrong type of automatic transmission fluid into your vehicle, it may become foamy. Check with your local auto parts store representative to ensure you are purchasing the correct fluid for the make and model of your car. If unsure, perform a thorough transmission fluid drain and fill it with the proper fluid.
A coolant leak may also cause foamy ATF. Fix coolant leaks immediately to avoid damaging your vehicle's engine.
A missing transmission fluid dipstick may cause the transmission to suck air into the fluid. Not all cars have a transmission dipstick, but if your vehicle came equipped with the hole for an ATF dipstick, you should always have the dipstick installed. Look for replacement dipsticks from an auto parts store.
