I have a 2003 Mazda MPV with a Ford 3.0l engine. I am having a high pressure, high temperature problem. The coolant is boiling back into the expansion tank, and the faster I go the hotter it get and more pressure it builds. I replace the waterpump, t-stat, and lower rad hose as it was soft. This scenario repeats no matter what I do. I asked an experienced engine builder his impression, with the reply combustion gases are leaking back into the coolant and causing it to boil. Do you agree and what do you suggest as a repair?
Aug 30, 2010 at 6:35 PM
