2008-2010 Ford 6.4L Powerstroke Cooling System Parts

Cooling system on the 2008-2010 Ford 6.4L Powerstroke

Ford filled the 6.4L Powerstroke with 7.66 gallons of Motorcraft Gold (VC-7-B) mixed 50/50 with distilled water. That coolant has more jobs than it does on most engines. The water pump hub and impeller mount in the front cover, and the pump has a built-in reservoir to catch normal seal seepage. From the front cover, coolant runs to the horizontal EGR cooler, then the vertical EGR cooler, then back to the cover. A small port at the top of the vertical cooler cools the EGR valve and doubles as the air bleed to the degas bottle. Between them, the two coolers pull roughly 850 F out of the exhaust before it reaches the EGR valve. Up front, Ford fitted a radiator about 33 percent larger than the one in front of the 6.0L.

What fails and why

The radiator is the one everybody knows about. The factory crimps between the tanks and the core separate and leak, and there is no repair option; the radiator gets replaced. Ford's Venturi-tee fix did not cure the seam leaks either.

Next are the small leaks. Weak degas caps and minor hose or connection leaks let the level drop, and low coolant turns into overheating under load. You see it on long grades, and it gets worse when you tow.

The oil cooler is the expensive one. Degraded coolant restricts its passages and the flow that feeds the EGR coolers. The warning sign shops look for is engine oil running about 14 F or more hotter than coolant. Owners report it in the 50,000 to 75,000 mile range, with a check engine light, de-rate, high oil temps and, left alone, EGR cooler failure.

Less common is cavitation in the front cover behind the water pump when the coolant runs low. The signs are milky oil, pinholes or coolant loss you can't trace.

Stock replacement vs. upgrade

For a leaking radiator, the usual fix is an all-aluminum radiator with welded tanks plus an upper support or tie bar that keeps the core support from flexing. If you want factory-style construction, OEM-style replacement radiators are here too. A coolant filtration kit is the other common add-on. It keeps a filter in the circuit so contaminants in the coolant get caught instead of collecting in the oil cooler.

Order of work matters. Any time a radiator goes in, pressure-test the system, replace the degas cap and hoses, and confirm the water pump is doing its job. Diesel Hub recommends keeping the coolant additive concentration and flush schedule up to limit cavitation. If the EGR coolers are already in trouble, fix the cooling problem first and replace EGR parts after. In practice both EGR coolers get replaced as a set, since getting to the horizontal one is the same job.

What we carry

Mishimoto covers the most ground: aluminum performance and replacement radiators, the upper support bar, radiator protection bundles, a silicone radiator hose kit, an aluminum degas tank, a high-temperature thermostat, a coolant filter kit and Liquid Chill coolant. XDP adds the Xtra Cool direct-fit radiator and Xtra Cool water pump, a black-phosphate water pump bolt kit, the XD177 coolant filtration system, an ECT sensor and a degas cap. Dorman supplies upper radiator and heater hose assemblies, a thermostat housing, the coolant recovery tank, an overflow hose clip and a clutch fan blade. Water pumps come from Dayco and Alliant Power. Dayco also has curved upper and lower radiator hoses, and Alliant Power has a thermostat kit, the EOT/ECT temperature sensor and its pigtail.

Mahle supplies the water pump gasket, thermostat housing gasket and radiator hose seal O-rings. CSF has an OEM-style radiator and an AC condenser, No Limit Fabrication has a replacement coolant tank with battery tray and a coolant replacement line, and PPE has an EGR valve gasket and O-ring set. For coolant, choose from Hot Shot's Secret, Lucas Oil and Mishimoto.

Fitment notes

The radiator, EGR coolers, oil cooler and front cover are 2008-2010 6.4L-only parts. Units from the 6.0L before it and the 6.7L after it do not interchange, and the 2011 Super Duty was an all-new truck. Some smaller parts are shared: the sensors, the pigtail and the degas cap list wider ranges such as 2003-2010 6.0/6.4L or 2003-2016 in their titles, so go by the title on each product. This engine went in F-250 and F-350 Super Duty pickups, the F-450 pickup and F-450/F-550 chassis cabs. Verify by VIN, or run the fitment checker on the product page, before you order.

Frequently asked questions

Why are there bubbles in my 6.4L degas bottle?

The degas bottle is where the system bleeds air, and it is fed from the top of the vertical EGR cooler. Bubbles there are the classic sign of a cracked EGR cooler letting exhaust into the coolant. Pressure-test before you buy parts, and keep in mind that a weak degas cap can cause coolant loss on its own.

Can the factory 6.4L radiator be repaired?

No. The leak comes from the factory crimps separating where the tanks meet the core, and there is no repair option. The fix is a replacement radiator; an all-aluminum, welded-tank unit with a support bar is the common choice.

What coolant does a 2008-2010 6.4L take, and when do I change it?

Ford specifies Motorcraft VC-7-B Gold concentrate mixed 50/50 with distilled water, 7.66 gallons. The first change is due at 100,000 miles or 6 years, then every 50,000 miles or 36 months after that.

Should I replace the water pump when I replace the radiator?

Not automatically, but check it. The recommended practice on a radiator job is to pressure-test, replace the degas cap and hoses, and confirm the pump works. If the pump does come off, look at the front cover behind it for cavitation damage while it is open.

Is a coolant filter worth adding to a 6.4L?

It is one of the most common add-ons for this engine. Degraded coolant restricts the oil cooler and the flow to the EGR coolers, and a filter in the circuit catches contaminants first. Mishimoto and XDP offer kits for this truck.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.