I am the member who wrote the quip.
I have used stop leak for old gasoline engines. I agree with what Capta stated. In general the channels of Diesel engines through which coolatn flows tend to be smaller than gasoline combustion engines. Marineized engines are especially vulnerable because of the frequent occurrence of rust in their systems. While it is possible that you could use such product in an emergency. I feel suggesting it's use as a viable resource for the type of problem of the poster is ill advised.
