My 2001 GT is almost 3 years old now. So my natural inclination is to change the coolant. However, I am not sure I want to, for several reasons:
1) It's still bright green in the recovery bottle (seems significant).
2) It's not time yet according to Ford (may not mean much).
3) I don't want to introduce air bubbles or "hot spots" into the cooling system.
#3 is the most significant factor. Every time that I, or a friend, changes coolant, the car always seems to take in less than it should. It seems like cooling passages are very convoluted, and air bubbles are inevitable. I think this has been proven by Smokey Yunick among others; there will be air trapped in the system, it is just a matter of how much. I know the Windsor motors (302, 351) are susceptible to this, but I do not know to what extent the Modular motors are.
Related to #3, the more auto maintenance I have done, the more I am inclined to leave things alone unless there is a truly compelling reason not to. In other words, "if it ain't broke, don't fix it."
Any opinions? Has anyone with a 4.6L changed their coolant with positive/negative results?
EDIT: I guess that if the factory doesn't use a special fill procedure, which is different from what the dealership's mechanics would do, then there is no issue. Does anyone know if they do anything special at the factory to avoid trapping air in the system?
1) It's still bright green in the recovery bottle (seems significant).
2) It's not time yet according to Ford (may not mean much).
3) I don't want to introduce air bubbles or "hot spots" into the cooling system.
#3 is the most significant factor. Every time that I, or a friend, changes coolant, the car always seems to take in less than it should. It seems like cooling passages are very convoluted, and air bubbles are inevitable. I think this has been proven by Smokey Yunick among others; there will be air trapped in the system, it is just a matter of how much. I know the Windsor motors (302, 351) are susceptible to this, but I do not know to what extent the Modular motors are.
Related to #3, the more auto maintenance I have done, the more I am inclined to leave things alone unless there is a truly compelling reason not to. In other words, "if it ain't broke, don't fix it."
Any opinions? Has anyone with a 4.6L changed their coolant with positive/negative results?
EDIT: I guess that if the factory doesn't use a special fill procedure, which is different from what the dealership's mechanics would do, then there is no issue. Does anyone know if they do anything special at the factory to avoid trapping air in the system?