If your car has transmission problems after sitting in a hot garage all summer long without cranking or driving it, check the gas tank for water and sludge. Sometimes, a car develops water in the tank after you expose it to humid conditions, such as your hot garage, then cool or cold air later, such as parking the car under shade trees. The warm air inside the car's gas tank cools down and condenses, or releases water into the fuel. Once you drive the car, watery fuel leaves the gas tank and travels to the transmission through its fuel lines.
Sludge from old or bad gas can also get inside your transmission and keep it from working properly. Sludge contains impurities, such as dirt and oil. You can remove the water and sludge in the tank and clean out the transmission's fluid compartment to see if you solve the problem. Here's what you do.
Drain the Gas Tank
The first thing you want to do is drain or siphon the gas tank. You can siphon the gas with a special kit purchased from your local auto store. The kit contains a pump and hose to remove the water and gas mixture from your fuel tank.
Here's you siphon the tank:
- Place the car in a shady area, then open and remove the gas tank's cap.
- Insert the siphoning end of the pump's tubing into the gas tank, then place the other end into a portable fuel container.
- Use the hand pumping mechanism on the pump to suction the watery gas into the tube.
- Wait until the contents of the fuel tank empty completely, then replace the cap.
You can now refuel the car. Start the engine, then wait 15 minutes for the gas to circulate through the car. Turn the car back off and move to the next step.
Clean Out the Transmission
You need to lift the car on a jack and ramps, as well as place it on a flat surface to keep it steady and safe. Once the car's secure, open or remove the flushing valve, plug or bolts placed beneath the transmission, and allow the fluids to drain in a large container. Close or replace the valve, plug or bolts, then pour a transmission fluid cleaner inside the reservoir. Start the car to give the fluids time to circulate through the transmission.
After waiting 5-10 minutes for the cleaner to work through the transmission, turn the car off and drain the fluids out through the flush valve. The transmission cleaner will contain impurities, including the watery gas. Remove the ramps and jack from beneath the car, then restart the engine.
If your car previously knocked or made other bad transmission noises, see if these problems go away. Shift the car's gears to see if they do so smoothly. If the transmission stops having any of these problems, you fixed it. If the car continues to have problems, schedule an appointment with a repair company, like S & A Transmission, right away.
If you don't feel comfortable performing the steps above, have your transmission repair technician check the car instead.