Planning Ahead: Head Studs on a 6.4L

One thing most of us can agree on as diesel owners is that we’ve all been down that road, you know the one where our truck is getting a little hot pulling that grade with our toy hauler in tow, coolant starting to spray out of the reservoir cap or even worse, fuel in our coolant.

All of these symptoms are, for the most part, a sign of a head gasket failure. With the changes to newer model trucks including higher horsepower/torque numbers which leads to an increase in drive pressure it will continue to be an issue that will not go away. Today we will focus on the 6.4 Power Stroke; with its compound turbochargers system and dual egr coolers it is a recipe for head gasket disaster. Ford has come a long way from the 6.0 TTY (torque to yield) head bolts by switching to factory installed larger head bolts (16mm) torqued to 165 lb-ft, but they are still not perfect. In the interest of going for perfection we are turning to Alliant Power and their 6.4 head gasket kit to help us solve the last weak point. On this particular vehicle we have previously addressed a number of the common 6.4 concerns including replacing the EGR coolers with both horizontal and vertical Bulletproof Diesel EGR coolers, we’ve replaced the oil cooler, and replaced the high pressure fuel pump which are all fairly common failure points of the 6.4 Power Stroke so today we will we will put the last piece in the puzzle.

We turned to the pros at Bud’s Diesel in Orange County, California and two of their technicians Hector Lezama and Julio Lezama to install Alliant Power’s complete 6.4 head gasket kit. As we unboxed the kit from Alliant Power we can tell they have done their homework as far as components necessary to complete the repair are concerned, they have included components that others have left out. The contents include ARP head studs, head gaskets, exhaust manifold gaskets, rocker box gaskets, valve cover gaskets, 8 injector seal kits with fuel lines, intake gasket kit for egr system, complete turbo mounting kit, and oil cooler gaskets. This is truly a complete head gasket “kit” in a box with all parts needed to complete the job included. DW

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As Hector and Julio were removing exhaust components to gain access to the compound turbochargers they came across a few seized up-pipe bolts. It is very common on most Power Stroke and Duramax trucks that up-pipe bolts become seized due to constant extreme heat and cooling .

Now that the necessary up-pipe bolts have been cut and removed Hector was able to remove the turbocharger assembly and downpipe so they could gain full access to high pressure fuel pump and fuel lines that run to cylinder head. (This is also the perfect time to visually inspect the high and low pressure turbochargers for any shaft play or wheel damage)

Now that the turbochargers are removed you can see the technicians have full access to the high pressure fuel pump, high pressure fuel lines and oil lines.

With the exhaust components taken care of Hector and Julio will shift their focus to the intake manifold by removing the fan clutch (5), fan shroud, serpentine belts, horizontal and vertical EGR coolers (6), EGR valve housing and finally the intake manifold.

With the valve covers removed Hector and Julio begin to remove the fuel injectors, high pressure fuel rails and fuel injector lines. It’s worth noting that fuel injector lines are one time use. All you DIY’ers make sure you replace them any time they are removed.

After removing the rocker boxes they remove the rocker arms, rocker arm bridges and push rods to prepare for removal of cylinder heads.

Here’s everything removed from the cylinder head. Fuel injectors, fuel injector hold down, fuel injector lines, high pressure fuel rails, push rods, rocker arms, rocker arm bridges, and glow plugs. This is also a great chance to inspect rocker arms and rocker arm bridges for damage. It is very common for the 6.4 Power Strokes to exhibit abnormal wear patterns on rocker arms and bridges. Also pictured is the special fan clutch removal tool.

Now that the head bolts have been removed Julio can now start to remove the cylinder heads, here’s a great look into what kind of a beating your head gaskets take.

Once the cylinder heads are removed now is the perfect time to inspect the pistons and cylinder walls for any damage. After inspection Hector will remove all 16 hydraulic lifters to inspect for damage. After finding a couple with sticking rollers we decided to err on the side of caution and replace all 16 lifters with new factory replacements.

Since we are on the topic of lifters here is a disassembled view of a single 6.4 Power Stroke lifter. Note how small the needle bearings are and how the smallest debris in the oiling system can cause a big problem. Fun Fact: Located in the oil filter housing there is a bypass valve set at 27psi that once activated will force the engine oil to bypass the oil filter and become distributed throughout the engine unfiltered. A great way to avoid this is by changing your oil often and sticking to OEM oil filters.

With teardown complete Hector begins to clean the mounting surface on the short block with very light sanding to remove any debris from the old head gasket followed up with a chemical cleaning to remove excess debris left over to ensure a clean mounting surface.

Here’s a look at the Alliant Power head gasket kit. Included is everything we needed including head gaskets, exhaust manifold gaskets, rocker box gaskets, valve cover gaskets, injector reseal kits and fuel lines, intake gasket kit, EGR cooler gasket kit, turbocharger gasket kit, oil cooler kit, and least but not last ARP head stud kit.

While we can appreciate Fords attempt at solving their head gasket woes by upgrading the stock head bolts to 16mm and a heavier torque specification, there is still no comparison to the strength of a set of ARP head studs.

With the mounting surface cleaned and head gasket installed from our Alliant Power kit it is very important to make sure that the cylinder head alignment dowels are reinstalled (top left and top right corners).

Before installing the ARP studs from our Alliant Power kit it is very important to generously coat the end of the stud with ARP Ultra-Torque assembly lubricant (included). ARP Ultra-Torque will eliminate the possibility of a false torque reading and will ensure consistent fastener preload for every head stud.

After installing the ARP studs into the block hand tight, Hector and Julio installed a fresh set of rebuilt cylinder heads which is something they do at Bud’s Diesel for every head gasket job and applied more ARP Ultra-Torque to the top of the studs and washers.

With the ARP head studs lubricated and tightened hand tight Hector begins the hefty torque sequence for these monstrous 16×2.0 head studs. The 6.4 Powerstroke ARP head stud kit has a 3 step torque sequence starting at 90 ft-lbs and finishing at a staggering 275 ft-lbs which is exhausting to say the least but really shows how much of an upgrade the ARP head stud kit is when you are torqueing it 110 ft-lbs more than stock.

Julio begins the reinstallation of push rods and rocker arms following factory specific torque specifications for all components prior to installation of the rocker box and fuel components.

With the rocker boxes installed as well as the high pressure fuel rail and fuel injectors, Hector finishes torqueing the fuel injector hold-down clamps before installing fuel lines since they obstruct some of the bolts.

Installing the new fuel lines from our Alliant Power kit is easy when you have the proper tools. Hector is using a special crow’s foot attachment to torque the fuel lines to factory specifications.

Installation of the intake manifold using the intake gasket kit is a breeze when you have a set of helping hand and also is the last step before installing high pressure fuel lines and turbochargers.

As you can see, installing the series sequential turbochargers is a two person job with not only their weight but awkward size it’s a task that Hector and Julio are glad to complete.

Finishing up the small odds and ends prior to the cab being lowered and fluid being refilled, a huge thank you to Hector Lezama, Julio Lezama and the rest of the staff at Bud’s Diesel for showing us that “planning ahead” can keep your 6.4 Power Stroke on the road for years to come.

Fuel in Oil

Due to the regeneration system of the 6.4 Power Stroke it is very common for the presence of excessive amounts of fuel in your engine oil. Fuel robs all lubricity from the engine oil and can cause catastrophic engine damage (Pictured). The most common part that fails are the hydraulic lifters which in turn will damage the camshaft causing groves or flat spots which will start the slippery slope of engine failures. The best course of action for any 6.4 owner is to change your oil more frequently and check oil levels often in between oil changes.

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Nick Leon

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