I have heard of using black pepper, in fact a friend of mine did it on his VW golf with the plastic radiator. it had a crack that leaked coolant out the top. he put black pepper in it while it was idling, and we watched the leak diminish to nothing. he drove it that way for months, than sold the car. I warned him at best it was a temp fix, and I was surprised it worked at all on such a big crack. He said it always has worked for him.gnarnold wrote: ↑Wed Mar 13, 2019 1:31 am I...have heard of people using a raw egg for leaks one time In was in an desperate situation and used black pepper it worked for a while until the smog guy put it on his dynamo and full throttled it like a jerk and ruptered the crack at the top of the rad on the plastic part .needless to say he was a little mad that his new dynamo machine was bathed in nice hot peppery smelling coolant .300 bucks and look the other way I still passed smog .it sure was funny .
When I was in collage a friend of mine said that "red pepper" works, it is much finer mixture of particles, mostly plant fibers ground very small. I have also heard of using raw egg. that does not seem like a good idea at all, not very durable if it does work, and who knows where it would end up. at least the tiny plant fibers would stay in suspension in the coolant mix.
Next up, eggs, salt and pepper, with a side of bacon to keep the water pump lubricated.