The Reasons Engine Oil Becomes Contaminated With Water. There are times when you may realize that there is an increase in the oil level of your engine and you may have questions in your head about how that happened. Well, it can be one of two contaminants in the engine oil – coolant, water or fuel. We’re going to show you the ways that they may enter or contaminate your engine oil. Coolant water may contaminate your engine oil in the following ways: There may be a leaking head gasket which may be caused by overheating, which may lead to contamination between the compartments of the engine.. There may be cracks in the cylinder head or block, which may be caused by overheating or frost damage.. There may be a failed seal around the bottom of the wet liner, resulting in the incorrect coolant mixture.. There may be a corrosion of wet liner or a porous block. This may be caused when there are no corrosion inhibitors in the coolant, which causes sludge formation that may corrode the wall and pierce the cylinder wall.. There may be heat exchanger failure, which may leak fluids between the systems. That may cause oil to get into the coolant system.. There may be an uncovered vertical exhaust pipes (like those on tractors) that have been left outside in the rain, will fill up with water, eventually finding a path to the engine.. Fuel may contaminate your engine oil in the following ways: There may be the fuel lift pump, which has a diaphragm that can split and provide a route for the fuel to enter the engine crank case.. There may be the injector pump shaft seals, which have failed.. There may be leaking injector nozzles during periods of inactivity and they can drip their contents into the cylinder. That causes the fuel to run down between the piston and bore the sump.. If you are looking for small engine repair services in Ottawa, mobile car battery boosting, lawn mower and lawn tractor repairs and tune-ups, or snow blower repairs then give us a call to book your mobile small engine repair today. We fix, repair, and tune-up small engines such as lawn mowers and snow blowers and garden equipment. The best part is that we come to you so no more waiting in line or traveling back and forth to fix your small engine equipment.