This 6.0L Power Stroke oil cooler rebuild kit came from MKM Customs, which in addition to offering aftermarket products, keeps a host of must-have OE items on its shelves. The most common failure on factory oil coolers is due to the coolant side of the oil-to-coolant aluminum heat exchanger’s internal passages plugging up with debris. On a more catastrophic (yet rare) note, the factory oil coolers can rupture and contaminate the cooling system with oil (and vice versa). This 6.0L Power Stroke oil cooler rebuild kit came from MKM Customs, which in addition to The oil used in the ’03 to ’07 Ford 6.0L Power Stroke HEUI injection systems is the hardest working petroleum in the world. As you can imagine, engine oil that’s pressurized as much as 3,600 psi gets pretty hot, and not being able to adequately control the oil’s temperature can lead to a host of engine problems. Welcome to one of the most common failure points on the 6.0L Power Stroke: the oil cooler. Specifically, the minuscule coolant passages within the oil cooler’s fluid-to-fluid heat exchanger plug up over time. And as coolant is used to cool the oil, this blockage hampers heat transfer and eventually superheats the engine oil. With the turbo, alternator, fuel and oil filter reservoirs, and intake manifold out of the way, the oil cooler can be unbolted and pulled from the lifter valley. With the underside of the oil cooler submerged in oil, it’s also ideal to allow it to drain a bit before disassembly (although no matter what you do, the heat exchanger will still be full of oil until separated from the cover). With the turbo, alternator, fuel and oil filter reservoirs, and intake manifold out of the An easy way to tell you’ve got a failing oil cooler is by comparing engine coolant temperature (ECT) and engine oil temperature (EOT) with a scan tool. As a general rule of thumb, the two temps should stay within 15 degrees of each other when the engine is up to operating temp. Needless to say, with oil temperature spiking to 230 degrees and engine coolant remaining at or near 190 degrees, it was easy to diagnose the problem on our ’03 F-250. Just like last month’s head stud install, we’re once again opting to save money and rebuild the oil cooler ourselves, as well as add a coolant filtration system to make sure it never fails again. Read on to see our oil cooler fix for Project Outcast. Tip of the Month According to Ford, 9 times out of 10, EGR coolers fail as a direct result of a failing oil cooler. So if you’re still sporting the factory EGR system (our F-250 is not), you will want to look into rebuilding the oil cooler in the event you experience a failed EGR cooler. Then the leftover oil in the lifter valley was suctioned out, as were all oil and coolant passages, along with the mounting bolt holes. This was also an opportune time to clean up the mating surface on the block. Then the leftover oil in the lifter valley was suctioned out, as were all oil and coolant Since it’s made of a very fine mesh, it’s common to find a tear in the screen on the pump inlet strainer. The strainer sits in the lifter valley under the oil cooler and is the last line of defense for catching debris before oil makes it back to the high-pressure oil pump. The oil cooler rebuild kit comes with a new inlet strainer. Since it’s made of a very fine mesh, it’s common to find a tear in the screen on the pump After removing the oil filter base and EGR coolant supply cover, we pulled the two mounting bolts for the heat exchanger (shown). Some key items needed to perform the rebuild are T30 and T45 Torx bits, and an inch-pound torque wrench. After removing the oil filter base and EGR coolant supply cover, we pulled the two mountin With the oil cooler cover resting on two 4x4-inch boards and the heat exchanger hanging between them, a socket and hammer were used to dislodge the heat exchanger. It’s important to use a socket 13⁄16 inch in diameter or smaller here because you don’t want to damage the inlet and outlet ports on the oil cooler cover (it gets reused). With the oil cooler cover resting on two 4x4-inch boards and the heat exchanger hanging be Since we pulled both the turbo and oil cooler, we decided to install Ford’s updated turbo oil drain (top) and turbo oil feed line (right). However, in order to run the updated (solid) oil feed line on ’03 to ’04 1/4 engines, a later-model oil filter base cover has to be installed. Luckily, Ford sells an all-inclusive adapter kit, which comes with the filter base, feed tube, feed tube gasket, O-ring, and hold-down bolt. Early 6.0L engines used a turbo oil feed line with a flexible, braided steel section, which was known to deteriorate internally. Since we pulled both the turbo and oil cooler, we decided to install Ford’s updated turbo As we’ve shown you in the past (Oct. ’11), the tiny internal coolant passages in the heat exchanger are prone to gumming up over time—and they end up looking like this. If you look closely, you can see that virtually every other row of passages is completely plugged. As we’ve shown you in the past (Oct. ’11), the tiny internal coolant passages in the heat While rebuilding the oil cooler, it’s important to clean the sealing surface and inspect the covers for damage. Also, make sure the small oil cooler cover vent hole is clean (use compressed air), and that the oil cooler cover drain hole is free of debris (we used a paper clip, shown). While rebuilding the oil cooler, it’s important to clean the sealing surface and inspect t The rebuild itself is very straightforward, with O-rings and gaskets being easily removed and replaced, and a new heat exchanger being swapped out for the old one. Here you can see the new oil cooler cover gasket being installed in its respective groove. Ford’s rebuild kit also comes with detailed instructions, and though this is a big job, even novice mechanics can tackle it if they take their time. The rebuild itself is very straightforward, with O-rings and gaskets being easily removed Switching to the newer-style oil filter base called for swapping over the oil filter stand, as well as the factory engine oil temperature and oil pressure sensors. If you find yourself performing this update, don’t be alarmed that one of the three mounting bolt locations in the new oil filter base (for the oil filter stand) isn’t threaded: the bolt will self-thread. Switching to the newer-style oil filter base called for swapping over the oil filter stand Following Ford’s recommended specs, the oil cooler cover assembly fasteners receive 192 in-lb (16 ft-lb), the oil filter base mounts to the oil cooler assembly and calls for 204 in-lb (17 ft-lb), and the EGR coolant supply cover bolts (shown) get torqued to 85 in-lb. Following Ford’s recommended specs, the oil cooler cover assembly fasteners receive 192 in To ease the startup process later on, we filled the oil cooler galley in the block with fresh Shell Rotella T6 5W-40 synthetic oil. Then the rebuilt oil cooler was installed. To ease the startup process later on, we filled the oil cooler galley in the block with fr If you want your fresh oil cooler to live a long life, we highly recommend installing a coolant filtration system. This bypass-style system from River City Diesel takes the larger contaminants out of the cooling system, keeping them from collecting and (eventually) blocking the coolant passages in the heat exchanger. River City’s coolant filter kit comes with a 27-micron filter (Napa PN 4070) and utilizes ball valves at the inlet and outlet of the filter head to simplify filter changes. If you want your fresh oil cooler to live a long life, we highly recommend installing a co Parts List Total $797.15 Part: Vendor: Details: Price: Oil cooler rebuild kit MKM Customs Ford PN 3C3Z-6A642-CA $310 Coolant filtration kit River City Diesel Keep large debris out of oil cooler $159.99 *Oil cooler adapter kit Crossroads Ford Truck Sales ’04¼ to ’07 oil filter base/cover, solid turbo oil feed tube, Ford PN 3C3Z-6881-CA $195 *Turbo oil drain tube Crossroads Ford Truck Sales Freer drain backflow for turbo oil, Ford PN 6C3Z-9T515-A $24.38 Motorcraft Premium Gold Engine Coolant Crossroads Ford Truck Sales Flushed and replaced coolant; mixed 50/50 with distilled water, Ford PN VC-7-B $55.80 (4 gallons) Intake manifold gaskets River City Diesel Ford PN 3C3Z-9439-AA $51.98 (2) * = not mandatory EGR’s Effect On Engine Coolant… Did you know Ford recommends testing the 6.0L’s coolant every 15,000 to 20,000 miles? This is because it’s used to cool exhaust gas temperature passing through the EGR cooler from as much as 1,250 degrees to roughly 350 degrees. And it only has about 20 inches of travel time to pull off this tremendous heat reduction. It goes without saying that the 6.0L is hard on coolant. In this photo (sent in by a reader who’d just purchased an ’04 F-250), you can see what happens to coolant if it’s neglected long enough. The left-most milk jug contains a sample from the first coolant flush. From left to right, the jugs contain samples gathered from each subsequent round of flushes. After flushing the system eight times, it was finally clean. The engine was completely stock, was presumably running the original coolant, and had 83,000 miles on the odometer. SOURCES River City Diesels 136 Thunderbird Lane East Peoria IL 61611 1-309-699-2488 http://www.rivercitydiesel.com/ Crossroads Ford Truck Sales 800-593-3673 www.crossroadstrucksales.com MKM Customs 877-692-4110 www.mkmcustoms.com By Mike McGlothlin Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!