Well, dang. W/o I've seen an air hammer work, pound bolt back to break loose. V6 starter will pop it loose, but I4 spin wrong. Best idea is an old drive (old cause ya gotta cut it, drive ie: alt) belt, if you wrap it around something (like 3/8" ratchet handle) and crank pulley, and jam it tight (between x-mem and frame work) it will hold, I've done it.
That air hammer was nuts, even my 1/2" impact wrench would NOT move it.