I have a 97 T444E with 7.3. I had oil in coolant issue so I changed the oil cooler. In the process I broke the timing cover, si had had to change that also. Everything was changed with new parts except HPOP. I got all that fixed then it overheated quickly. I saw oil coming out of passenger head exhaust ports so I pulled the head and had it tested and serviced. Changed the injector cups and new o rings on injectors. Put it all back together and now the coolant system is getting pressure in it. I did a combustion gas test several times this weekend and it passes. Every time. Where else could this pressure be coming from.