The biggest common failure is the EGR cooler. All cooler failures can be attributed to a lack of coolant flow from the engine oil cooler. It has been directly linked to head gasket failure. The EGR cooler will develop a leak causing a loss of engine coolant out the exhaust and into the intake when the EGR is opened. In many cases, through a horrible series of events, this will lead to a catastrophic engine failure due to overheating, or coolant entering the combustion chambers. If you have such an issue or plan to power up your 6.0L, insist on having the cylinder head bolts replaced with studs. The EGR valve and passages are also prone to carbon build up.

An EGR cooler failure can cause Fuel injector failures. The same motor oil which is used to lubricate the engines vital parts is the same oil that is used to drive the injectors. Coolant contamination due to an EGR failure will ruin the spool valve in the injectors over a short period of time. If you are experiencing coolant loss, the truck should be brought in for service immediately. By ignoring or simply adding coolant, there is a chance to have even more expensive repairs.
This platform has a very specific coolant requirement. The coolant used in your 6.0L PSD has been specified by Ford to ensure the longevity of cooling system components. This coolant is ethylene glycol based. It is significantly different than other ethylene glycol based coolants. It is whats called a HOAT/G05 coolant. Do not put Dex-Cool in your 6.0L PSD. Using only the recommended coolant and a reduction in change out intervals will prolong the life of your cooling system and keep the EGR cooler and oil cooler alive. Personally, I use Fleetrite ELC, as that is what INTERNATIONAL recommends for these motors. Many people neglect the cooling system on their truck. It should be tested at least yearly for PH and freeze/boiling point. There is an additive available from Ford that can be used in the 6.0 liter diesel. Due to oil cooler problems, I strongly recommend the installation of a coolant filter system to trap sand, iron shavings, and silicate crystals formed from cooling system neglect. The installation of a coolant filtration system will help, but we recommend flushing the entire cooling system, including the block, every two and a half years regardless of mileage. This will remove much of the sedimentary material that is known to block the oil cooler.

The next item of issue was the variable geometry turbocharger or VGT. This is the heart of the performance of a 6.0 liter. It provides a relatively quick spool up, thus providing an off the line acceleration that can be considered astounding for a seven thousand pound Truck. And if you drive a 6.0, you've experienced this first hand. This turbocharger is the heart of the outstanding performance of a stock 6.0 liter powerstroke diesel.

There are many performance issues related to the VGT system. Most times they are caused by sticking components of the VGT. These can usually be addressed by removing the turbo assembly, inspecting the components, cleaning them and reinstalling.

The easiest way to diagnose a turbo issue is with the Ford IDS system, there are available tests which help to determine VGT performance. The VGT is operated by a solenoid, the VGT solenoid, engine oil pressure is fed to the turbo. This oil lubricates the bearings and provides a means to drive the VGT piston. The VGT solenoid is a pulse width modulated component. It receives a command signal from the PCM based on inputs from the Maf, Map, Baro and EBP sensors. A failure in any one of the sensor circuits or the components will cause boost performance and driveability concerns.

The turbo itself is made up of several components. The compressor wheel, the turbine wheel, the center section, the VGT piston, the unison ring, the vanes and turbine housing, the compressor housing and VGT solenoid. The main problem we have found with this system is the unison ring. It is driven by a tab which is geared to the VGT piston shaft. This tab fits into a slot in the unison ring. The ring rotates a certain amount of degrees in both directions. There are vanes which are installed on pegs in the turbine housing. They are also attached to the unison ring with tabs which fit into slots. These slots allow the vanes to direct exhaust gasses onto the turbine wheel during conditions where velocity is lower, such as at lower RPM's, this allows the turbo to "spool" quicker providing more boost at lower engine speeds. Closing the vanes down also increases exhaust back pressure during warm up cycles and during an EGR flow event.

The later programs provide a sweeping of the turbo unison ring to help reduce sticking. Most of the sticking is due to a buildup of deposits on the inner part of the unison ring where it contacts the center section. This is often over looked when cleaning the turbo. We have had reman turbos from Ford that would stick right out of the box because the unison ring was too tight in this area. Special attention should be made when cleaning this part of the turbo. The unison ring should fit rather loosely and the piston should move smoothly when the unison ring is placed onto the center section for fitting. Also, the unison ring should be carefully inspected for cracking on the inner edge where the slots meet the edge. A crack in this area will cause the ring to stick against the center section as well. A careful inspection of the turbine wheel will reveal any defects in the wheel and tell you whether the turbo has been subjected to sustained high EGT's or debris. Play in the turbine shaft should be checked as should the seals for any oil leakage.

EGR Valve. EGR valve issues are common especially where a truck is idled for extended periods of time. Periodic cleaning is recommended to remove the soot deposits which will form and in many cases cause the valve to malfunction.

Fuel Injection Control Module (FICM). The FICM controls fuel injection timing and on time-PW (pulse width). The injectors are controlled electronically by the FICM based on input data from the PCM. It send a 48 volt signal to the injectors which have two coils that energize to pull a valve(spool valve) open and closed. The opening and closing of the spool valve allows oil from the high pressure oil system to operate the amplifier piston in the injector which in turn pressurizes the fuel within the injector, and injects fuel directly into the combustion chamber at the precise moment where the fuel mixes with air that has been heated by compression to a temperature which is high enough to cause auto ignition of the fuel.

The high pressure oil system consists of a gear driven oil pump, plumbing, a pressure control regulator, an injection control pressure sensor and oil rails which sit above the injectors.

Cooled oil is drawn out of the high pressure reservoir into the high pressure oil pump. The amount of pressure is controlled by a regulator mounted to the high pressure oil pump cover, it is then sent from the pump to the oil rails through a branch tube and stand pipes. The system monitors oil pressure and adjusts according to demand. The higher the oil pressure, the higher the fuel injection pressure. The oil pressure is amplified at a ratio of around 8:1. Fuel pressures can reach 26k PSI at the injector. This allows for much better fuel atomization, reduced emissions and more power.

The fuel injectors are a very precise piece of engineering. They require clean fuel and clean engine oil in order to operate trouble free. They have a condition which has been described as static friction or sticktion. The condition presents itself during cold start up and is more prevalent in colder climates. To eliminate or reduce this condition engineers have come up with a new program which pulses voltage to the injector coils after the main voltage pulse. This causes a rapid heating of the area around the coils which heats the oil that is trapped in these areas and reduces hydraulic latching of the spool valve.

This hydraulic latching is what causes a cold start misfire. It slows down the movement of the spool valve. This is why the engine runs better after it warms to operating temperatures. The oil viscosity is reduced and allows the valve to move more freely. Running 10w30 motorcraft diesel oil during winter months in cold climates will help as well, but the only way to solve this issue is by reprogramming with the latest flash. You can also use synthetic oil to help.


Heat and friction within or around the injector will also cause failure. High pressure oil system leaks have also been known to plague the 6.0 PSD. Oil leaks can happen at the branch tube, STC fittings, or any of the plugs in the oil rail and at the top of the injector where it meets the rail. A leak can cause anything from a hard start when hot, to a no start. This condition is fairly easy to diagnose with the proper equipment and tools.

Oil cooler failure. There are a couple of ways in which an oil cooler can fail. The oil cooler is a heat exchanger which sits below the oil filter housing. Oil is pumped through the heat exchanger which also has coolant flowing through. Coolant flows through the oil cooler to the EGR cooler then back into the cooling system. The coolant part of the oil cooler can easily become restricted with cooling system sediment. When this happens the oil temperatures will rise and spike causing the oil to break down and degrade and can lead to injector failure and will cause EGR cooler failure and ultimately head gasket failure.

Another way the oil cooler heat exchanger can fail is that it will develop a leak between the coolant and motor oil. This allows oil into the cooling system. This makes quite a mess and is tough to deal with. One of the best ways we've found on extreme failures is to pull the plugs on the block, remove the radiator hoses and let both the radiator and block drip for about 24 hours. This can then be followed up with a flushing procedure outlined in the Ford TSB. We've had the best results by having the radiator flushed of sludge in the worse cases.

You should never do any type of flushing after the installation of a new oil cooler heat exchanger until the block and radiator have been drained and flushed first. This will help remove any sediments that have collected and are loose. Most of these sediments tend to settle in the block, so flushing the block by itself first is a great idea. Otherwise the sediments can be picked up and make their way to the oil cooler during flushing, and never put any type of stop leak in your 6.0 liter powerstroke diesel!




We have had trucks come in which have experienced multiple oil cooler failures. Some have even had the exchanger replaced less than a week prior. What we have found is that unless you drain and completely flush the cooling system of sediments, you can have a repeat failure. In cases where there is evidence of extreme sediment, we always send the radiator in for cleaning and flush the heater core by itself and the block with the exchanger removed. This will prevent the possibility of flushing sediment into the exchanger where it can restrict coolant flow resulting in elevated oil temps and a blown egr cooler, and ultimately head gasket failure.


EGR cooler failure is generally caused by a restricted oil cooler. What little coolant makes it way to the EGR cooler will flash boil under certain conditions causing the cooler to break, or in some cases burst. The early signs of an EGR cooler failure can be slight loss of coolant, steam on a cold start or after a hot soak. More advanced stages of EGR cooler failure will be steam out the exhaust pipe, coolant dripping from the exhaust system and in many cases, a hydro locked cylinder or two. A hydrolocked cylinder will generally happen after a hot soak but can also happen after an overnight soak.

It is important to note that a hydrolock condition can cause serious damage to piston rings, connecting rods, injectors, head gaskets and starters. If you notice any of these symptoms, get your truck in for diagnosis and repair right away!

Head gaskets. A head gasket can fail at any time. They will generally fail under high load and heat conditions. It is possible to not ever notice the early stages of a failed head gasket until you pull a load. We've seen this many times throughout the years. One of the tell tale signs of a blown head gasket is a white residue on and around the coolant de-gas bottle. A failed EGR cooler can produce some pressure, but generally not enough to blow coolant out of the bottle. There is a pressure test we use to determine a failed EGR cooler in which the idle is brought up to about 1200 rpm, the VGT is set to maximum back pressure. If the cooler is leaking it will cause exhaust pressure to enter the de-gas bottle through the degas line which comes from the intake manifold, but never enough to blow coolant from the cap on a properly leveled cooling system.

Many of the symptoms of a blown head gasket on a conventional gasoline powered engine do not apply to this platform. For instance, on a gasoline engine, you can expect to find combustion gasses in the cooling system. On most failed 6.0 liters you will not be able to test in this manner because the problem can often not be duplicated in the bay. This requires the development of new procedures to diagnose the condition. Over the years we have developed these procedures and can diagnose a blown head gasket with accuracy.

A 6.0 liter PSD with a blown head gasket will often (except in extreme or advanced cases) not show any signs of overheating such as a conventional gasoline platform would. This is partly due to the large capacity of the cooling system, nearly seven gallons of coolant. It can overheat if the coolant level becomes to low. Interior heater performance will usually be the first sign of low coolant due to air being trapped in the heater core, but if you see the white residue on and around the coolant de-gas bottle there is a very high probability you have a blown head gasket.
Cylinder head machining. Both Navistar and Ford motor company have determined the cylinder heads on a 6.0 liter PSD should not be machined. They have a procedure for checking flatness, and if they pass this test they can be cleaned and reinstalled, there is however a problem with this method. One of the problems with doing this is that I have not seen too many 6.0 cylinder heads that did not have a high degree of pitting and erosion in the areas where coolant has been in contact, both on the cylinder head surface and the block deck surface. This pitting can be attributed to cooling system neglect. Also, on many of the higher mileage engines, there are often cracked exhaust valve seats or carbon pitting on all the valve seats. The retail cost of a new 6.0 cylinder head runs about $1600.00. The average cost to repair a set of cylinder heads runs about $800.00. These heads can usually be machined flat by only taking off .003 to .005. .005 is the limit we have set for our cylinder heads. Any more than this could cause potential issues with compression ratios, valve clearance and valve lifter preload. We have not seen a single machining related failure in the years we've been doing them and many of the trucks are fleet vehicles which get used hard and get many miles put on them. We have gone up to .008, but you need to measure several things to be safe. We have been installing head gaskets on the 6.0 liter PSD for the past six years, during this time we have not had one repeat head gasket failure. Almost every head I have checked, including new ones, have been warped.

As you can see, the 6.0 liter Powerstroke diesel has some problems. THE END. PHEW.....HAPPY NEW YEAR!!!!!!

 

Matty, in reference to your statement: (The later programs provide a sweeping of the turbo unison ring to help reduce sticking.) I have a 2006 F250 w/ 6.0 PSD that just had arp studs & head gaskets done and received a new flash with this work. The flash has the ECT/EOT differential monitoring of the 15* spread that puts the engine in limp mode if it exceeds this amoount. Should the sweeping of the turbo programing be included w/ what is to be the latest flash for the 6.0 as described?

 

yes It should be sweeping the vains. there are some peramaeters to meet however.

 

Thanks Matty for that incredibly detailed write up!

 

first off Matty great right up.

"Head gaskets. A head gasket can fail at any time. They will generally fail under high load and heat conditions. It is possible to not ever notice the early stages of a failed head gasket until you pull a load. We've seen this many times throughout the years. One of the tell tale signs of a blown head gasket is a white residue on and around the coolant de-gas bottle. A failed EGR cooler can produce some pressure, but generally not enough to blow coolant out of the bottle. There is a pressure test we use to determine a failed EGR cooler in which the idle is brought up to about 1200 rpm, the VGT is set to maximum back pressure. If the cooler is leaking it will cause exhaust pressure to enter the de-gas bottle through the degas line which comes from the intake manifold, but never enough to blow coolant from the cap on a properly leveled cooling system. "

Just an fyi...
I have seen failed only coolers cause degas bottle pumping. Its not common to say the least but it happens.

Next if you look at the deck hight spec and measure the head you may be surprised what you find. I have pulled heads out of the box that were right @ spec. so milling may be out all together.

yes the pitting issues are bad on some, however if the pitting is not in the fire ring it should not makee any differance. if you have found different please let us know.

Out of all the heads I have taken off I have not ever seen a cracked one... Got a pic?
I have found most 99% of cyclinder head are reusable the way they are. Give that statement most of the stuff I work on is 200k and under.

 

The deck height spec Cheezit is speaking of is, I believe, 3.74 inches. As for never seeing a cracked one, that is very surprising. They are almost always cracked out to the glow plug hole. Occasionally between valves. I will look for a pic, dont have any heads sitting here. As for pitting, yes you are correct, we dont see alot of engines where it is a problem. Just a little disconcerting.

 

Here is some cracked head pics.
UCF Machine Shop - Ford Diesel 32-valve head teardown and analysis.

Go to pics 2,3,4,5 etc.

 

the spec you are correct on :Cylinder head thickness — minimum 95 mm (3.74 in)
have you measured the deck hight on one yet? needless to say I was shocked.


stright from the workshop. so far in testing this has been accurate:

NOTE: Cylinder heads that contain carbon buildup in the coolant areas may show evidence of surface pitting when cleaned. Surface pitting in the coolant areas is not cause for replacement of the cylinder head.

NOTE: Staining of the metal surface is normal and does not affect sealing ability.

NOTE: Witness marks or indentations in the cylinder head resulting from the head gasket fire rings are normal and do not affect sealing ability.

NOTE: The surface finish on the cylinder head may appear to contain "record grooves", which is a normal condition.

NOTE: The cylinder head combustion chamber area may exhibit very small "surface fissures" or "microcracks" during a Magnaflux inspection process. These surface fissures or microcracks are typically located between the glow plug and the valve seats. They DO NOT extend into the coolant jacket and will not cause coolant loss or cooling system overpressurization. The presence of surface fissures or microcracks is not cause for replacement of the cylinder head.

Inspect the cylinder head for obvious signs of damage or distortion.

 

You mentioned that ford and international said that machining of the heads should not be done. However, that piece that vloney was to have taken directly from the manual stated that they cannot be machined.

There is a significant difference in verbiage between cannot and should not. I know it seems nit picking, but there really is a difference in the argument between the two.

Should not has more wiggle room then cannot, but the source that vloney said he was getting it from was straight from the ford manual said cannot.

Which one is it?

 

tex given a mill and a pice of metal you can machine anything you want to.
machining a head evolves cutting valve as well if you do it all right you can make it work.
Remember that as a ford tech's some of us are bound to follow the repairs outlined if we expect to be paid and have recorse to follow.
being bound by the aftermarket world is something very different.
please refer back to my comment about deck hight. all I can say is man they are close to that spec out of the box. If my mic was right I would say at or just under to start out with doesnt give much "wiggle" room if you will

 

I can GUARANTEE that the Ford dealers here send the heads out to be machined. They use the same machine shop we do. As for the cracks or micro cracks, we still use the heads as long as they pass the pressure tests. As for the head thickness, I can tell you we have used heads under spec, but it takes some additional work and parts to do it right. Sink valves, shim springs, shorten valves(not recommended) shorter pushrods(recommended). All to keep the geometry and P to V correct. We actually have one race motor out that the heads measured 3.68 inches. The customer didnt have money for heads and needed it NOW. We told him we couldnt guarantee it, but we would see what we could do. 2.5 yrs. later it is still fine. I DO NOT RECOMMEND TRYING THAT UNLESS YOU HAVE SOME SKILLS.

 

cheezit's point is valid. If we vary from Fords recommendations and don't get away with it we redo it at our cost, if cheezit does it and doesn't get away with it he loses his income for his family. In fact even if he does get away with it he may not get paid for not following Fords protocol. He has to play by a diff. set of rules than we do.

 

matty not surprised by that at all. we have a machine shop here in the metroplex that does them too.

But as 69cj stated Im not gonna do it. I dont like doing free work when things go south.

 

I can understand that position, but you have to remember that vloney extended that cannot be milled to the aftermarket just like his staunch anti-stud rhetoric.

Now if the skill was sooooooo hard to find that it took that 1 out of a billion people that could actually do it correctly, that would be something else.

Now considering matty, according to him, hasn't had a machine related failure while they have been doing this, that would also go against the cannot be milled in no uncertain terms(whether done by Ford or aftermarket).

However, this is very tangent to the original intent of this thread, so I'll shut up now and go back to the "shadows".

 

Great info here, thanks