DAMN 4K for an engine replacement? Is it a brand new engine? Id had better be cast from gold for that much. They mush be charging you a good bit for labor as a new engine shouldn't be much more or less that 2K. At least that's about what it's been for all of my vehicles.

Find a used or rebuilt one for less $$. In any case, I'd suggest getting your car working right again. Weed is great, but it's not gonna drive you to work and back every day.