Engine Cooling problem
1998 Ford Taurus 6 cyl Front Wheel Drive Automatic 170000 miles
I've got a 98 taurus, standard 3.0 six, that has ruptured three new coolant overflow tanks in the span of 18 months. These were from two different suppliers, so I am unwilling to believe " I just got three bad ones".
There has to be something that is causing this consistent failure other than a bottle design flaw. It shocks the heck out of me that a thick-walled plastic surge/overflow tank with a 16PSI release cap would regularly rip open lengthwise from heat and pressure.
One item that I've recently replaced as a possible cause of excessive system pressure was the thermostat, which seemed to never fully open when tested. I'm now running a 185-degree failsafe unit. In addtion, six months after a complete coolant flush, there was serious corrosion residue in the bottom of the split tank and in the remaining post-rupture coolant (last night).
However, there was plenty of flow to the overflow tank/bottle through the top return tube when I checked the system unpressurized (cap off), so no serious system blockage that I know of.
I've seen the bottle rupture and block corrosion in coolant talked about in TSB-1116/NHSTA-622646, but I can't find any mention of a fix, solution, or recommended action to stem the listed issues.
Any idea of what could be causing the consistent pressure failures of the tanks? Any clues as to why the tanks fail before the caps release? Any hints on stemming the rampant system corrosion present even with frequent coolant changes?
Wednesday, December 10th, 2008 AT 6:27 AM