Water is great — until it gets in your fuel
Fortunately the chances of getting engine running problems from excess water in fuel has been greatly reduced since fuel suppliers started improving their winter blends some time ago, but it can still happen. The symptoms are quite recognizable; the engine will suddenly develop a severe engine miss, strong enough to propel you forward out of your seat and spill your double-double. It usually comes on during accelerations when relatively large volumes of fuel are injected into the cylinders. It shouldn’t be ignored as it can cause internal damage to both the engine and transmission. Transmission torque convertors, for example, have been known to develop cracks due to the sudden and severe power surges from the engine when excess water is doing its worst.
Fuel suppliers add methyl hydrate or isopropyl alcohol to their fuel in winter to help stave off the problems that water can cause when the mercury dips. But their concentrations can’t do miracles if the water concentration gets too high. Fuel station operators are required to measure the amount of water in their holding tanks daily. To do this they treat the bottom of their long measuring dipsticks with a paste that changes colour when in contact with water. As gasoline floats on water they only need to be concerned with what’s on the bottom of their storage tanks. These tanks are primarily dipped to verify inventory levels but checking for excess water can be done at the same time and is still critical regardless of the supplier’s blending.
Avoiding water in fuel is a matter of choosing your refilling station. A higher volume site usually has fewer problems because their inventory turns over at a much faster rate. Keep an eye out at stations you may frequent for standing water on their lots during heavy rains. Tanks fill necks are supposed to be positioned high enough to avoid rainwater from getting into the tanks hence the noticeable pavement humps where their fill ports are located. But with age and soil settling, tanks can become prone to surface water intrusion.
If your ride suddenly develops symptoms of water contamination in the fuel, be cautious when checking out the de-iceing products at your local auto parts store. Avoid any fuel de-icer that lists ethanol or ethyl alcohol as an active ingredient. This substance is already in regular grade fuel and increasing its concentration can lead to long term problems such as corrosion developing on any metal fuel system components. There are also products specifically formulated for diesel engines and as you might suspect you don’t want to mix things up. Read the concentration recommendations on the product label; avoid the temptation to add too much. And if any driveability problems exist after a single dose of de-icer, it might be time to consider a shop appointment to remove the fuel if needed or dig further for another cause.