Washer fluid is not mean to clean your engine, period. There are other products out there to help you flush your engine oil before swapping. But somewhere in France, a guy made a mistake. A horrible mistake.
The photos below come from a BMW Facebook Group in France where they show some disgusting looking goop coming out from the engine. First with the green macha looking ice cream, flowing out from the oil pan.
Secondly, below is an image of what is under the valve cover of the poor MINI.
Yes, it looks like someone had a bad case of diarrhoea. Apparently, the poor guy purchased 5 litres of window washer fluid with the intention of topping up his window washer fluid in his car. Instead of pouring the fluid into the right compartment, he ended up pouring it straight into the engine where engine oil is normally poured in. He then drove off with the fluid and after driving for a while, he returned to complain about seeing smoke coming out from his exhaust.
Unfortunately, it was already too late and the damage has been done. So next time make sure that you read the labels properly and don’t pour washer fluid into your engine!