Serious Mistake: Woman Pours Windshield Washer Fluid Instead of Engine Oil

A woman who poured five liters of windshield washer fluid instead of engine oil accidentally created a major headache for herself.

In a video shared on Facebook, the mechanic who received the vehicle in his shop showed the result of her serious mistake: an engine completely covered in a beige mass resembling peanut butter.

“What you’re seeing is not caramel or peanut butter. It’s what happens when someone puts 5.7 liters of windshield washer fluid where the engine oil should go,” the narrator says in the footage.

It goes without saying that the ingredients in most windshield washer fluids, which typically include a mixture of water, detergents, and methanol, are not at all compatible with internal combustion engines.

When these substances are agitated by the crankshaft and valve train, they mix with the remaining oil and form this thick, foamy paste visible in the video.

According to the U.S. Department of Energy, even small amounts of water contamination can strip an engine of its protective oil film, causing metal-to-metal contact and accelerated wear.

The mechanic suggested that 5.7 liters of windshield washer fluid ended up in the engine. With so much non-lubricating fluid circulating, mechanical damage can occur almost instantly if the engine is running.

In the most optimistic scenario, the oil pump will push the mixture through the system, distributing the sludge to bearings, bushings, and cams. In the worst case, lack of lubrication can seize the engine, a repair that often exceeds the value of older vehicles.

Many commenters were shocked by the serious mistake, but others suggested that it’s not exactly uncommon, especially among inexperienced drivers or in vehicles with confusing layouts under the hood.

While some said they had seen it before, others even reported seeing people make the opposite mistake—putting engine oil into the windshield washer reservoir.

At the end of the day, if you are going to add any fluid to your car, the general recommendation is to always check your vehicle’s manual to ensure you are putting things in the right place.

Photo and video: Facebook. This content was created with the help of AI and reviewed by the editorial team.