If replacing an engine would not be economically sensible in whatever you're driving you should probably chance it running the intersection or whatever. If you

If replacing an engine would not be economically sensible in whatever you're driving you should probably chance it running the intersection or whatever. If you fail you're buying a new car, but if you blow up an engine you're buying a new car too. But you might not fail so the relative expected value is greater. I hope your horn works...