Mark Houlahan
Brand Manager, Mustang Monthly
August 25, 2011

Horse Sense: Before you begin swapping parts in an effort to lower your 5.0's temperature, make sure you have a real cooling problem and not just a dash gauge or sending-unit problem. A bad sending unit or gauge can scare you to death as it pegs "hot" even though there's no real cooling-system concern. Proper diagnostics will get the right parts replaced without wasting money.

If there's one thing that will stop you dead in your tracks, it's an overheating engine. Small oil leaks and squeaky brakes are things you can nurse until the weekend to repair. But a failure of your cooling system will not only leave you on the side of the road, late for work, or that all-important meeting, but it also can cause major damage to your engine, to the point of total engine seizure. Keeping your cooling system up to snuff and having it able to tackle whatever you throw at it is a major peace-of-mind project.

The Mustang's cooling system is comprised of several components, all made from different materials. First and foremost is the water pump. The 5.0 water pump is cast from aluminum and features a reverse-rotation impeller design, which is used with the single serpentine belt that drives the front dress. If you install a replacement water pump designed for standard rotation (it will bolt on), or if you change the belt routing so the belt's grooved surface (instead of the smooth back of the belt) rides on the water pump pulley while maintaining the reverse-rotation pump, your engine will not cool properly. The pump is beltdriven, so a serpentine belt in proper condition is a must as well.

Also driven off of the belt/water pump hub is the cooling fan and fan clutch. Mustang fans are notorious for cracking, and even losing fan blades, while the fan clutch often leaks the viscous clutch oil from its hub, causing the clutch to not engage the cooling fan. Of course, there are rubber hoses that transfer coolant to the radiator and heater core. Lastly, there's the thermostat that controls coolant temperature and flow through the engine. We'll look at all these areas and fix what is necessary to get this Mustang chillin' once again.

Photo Gallery

View Photo Gallery