Let me give you a real life example… My BMW 6’s engine is notorious for leaks and valve stem seal issues. I of course, enjoy both elements of this particular ownership quirk. I decided to experiment. I bought two cans of ‘Oil Stop Leak’ additive made by a reputable brand.
It works on the basis of conditioning and swelling seals back to their original size. I poured in the specified amount. And proceeded to drive for the 700 or so miles needed for it to start to take effect.
It worked after 20 miles…
It did indeed swell the seal. So much so that it broke the seal and a massive leak ensued, resulting in a recovery truck and my dear friend who happens to own a BMW service rescuing me as always. New seal. New oil. New filter. And a lot of work.
Be careful with additives!
I feel it is better to put something right, and if you are not in a position to do so, or the vehicle in question is financially not worth fixing, like mine, just keep topping it up. It may soldier on forever.
Anyone care to share their experience of experiments with potential quick fixes?