01 D2 boiling coolant after 10ish miles and coming out of overflow tube. Temp Guage goes up when this happens. Did a pressure test with auozone rent a tool and held steady at 15psi for 20 min. Curious if anyone has seen a cracked block, heads, sleeves etc and still had the truck show good on a pressure test? I ask because misfire in cylinder 3, and loooots of white exhaust smoke made me assume cracked block or slipped sleeve initially. Now I think something is clogged stuck etc. given the ok pressure test.