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Fuel Additive Bottle Caps

We have heard of this unfortunate and easy to make mistake. You want to take care of your truck and use products that can help promote good fuel quality and system integrity which includes a variety of fuel system additives. Typically these products come in small bottles that have caps containing a coated cardboard disc inside of the cap intended to provide a seal.
Apparently these discs are not adequately secured to the cap and may remain stuck to the top of the bottle. If you are not observant and begin pouring your product into the fuel filler of your truck and this seal is stuck to the top of the bottle it may come loose as soon as the liquid begins to flow taking the cap into the fuel tank along with it. So what you say and there is probably all sorts of junk floating about inside you fuel tank? Well, there have been many reports of 2011 and newer Super Duty trucks that have been stopped in their tracks when these seemingly harmless discs get pulled up against the fuel pick up causing a restriction resulting in low fuel pressure and an engine stalling event. When this happens there will be a loud whining sound coming from the fuel supply pump and a low fuel pressure warning on the instrument cluster. This condition will likely be an intermittent and random concern making it very difficult to verify and diagnose therefore you should keep this in mind. And for the vehicle owner reading this, remember to look at your additive bottle before pouring. It just may save you and a technician some headaches.

Repairing EGT Sensor Bosses

Diesel exhaust gas temperature sensors can seize, break off and sometimes damage the threads in their mounting boss during removal preventing the installation of a new EGT sensor rendering the diesel oxidation, diesel particulate or selective reduction catalysts useless. We have some repair advice to offer you from the best method of removing the sensors to repairing or replacing the mounting boss.

So you have a diesel truck in the shop that either won't start or has a check engine light on due to an EGT sensor concern. Your first step is to diagnose the concern and determine what the proper and effective repair will be. If an EGT sensor requires replacement, first inspect the entire exhaust system for damage including the tailpipe for the presence of black soot and other sediments or fluid that would indicate that the DPF is cracked or damaged in some way that it would require replacement to begin with.   Remove The EGT Sensor

As per Ford Motor Company and the experience of service technicians, the best method for removing these sensors is as follows:
Cut off the wire from the top of the sensor to allow a deep six point 13mm socket to be placed onto the sensor hex nut. Using an oxyacetylene torch carefully heat the sensor mounting boss until it glows bright orange. Using a breaker bar place the socket onto the sensor hex nut and loosen - allow the parts to cool. Inspect the sensor boss for damage - sometimes the sensor refuses to break loose, the nut beaks off, the threads will lock up after a few turns or the sensor will come out but the threads will be damaged. Depending on the results of your inspection the next steps may or may not apply.  
Repair Damaged Threads

If the sensor comes out and the threads are damaged they can usually be repaired. Using a 12mm X 1.25 bottoming tap Identified by the flat tip shown in the picture the threads can be re-cut allowing a new sensor to be installed. Do not use a thread chaser/repair tap as those tools are not meant to cut the threads but only clean them up and will not be effective. When cleaning the threads with the tap use caution to avoid damaging the EGT sensor sealing surface at the bottom of the mounting boss.

Replace The Mounting Boss

The following procedure requires the use of an oxyacetylene torch and a welder. You must also obtain a new sensor boss. This repair is not recognized by Ford Motor Company and is not covered by any warranty provision and the parts other than the sensors are not available from Ford. There are sources for these bosses but you have to search for them:
This source on EBAY will get you the right part. Search the Internet for "Exhaust Sensor Boss" or "Exhaust Sensor Bung" with 12mm X 1.25 threads Step 1 - Access the damaged sensor mounting boss either by raising the body on chassis cab trucks with a dump body or removing the catalyst from the truck to work on a bench. In some cases you may be able to simply disconnect the inlet of the entire aftertreatment assembly and disconnect the mounts from the frame and drop the assembly down enough to provide ample room to work.

Step 2 - Heat the damaged EGT mounting boss with an acetylene torch until it glows bright orange, then twist it off with a pipe wrench.




Step 3 - Once removed you need to clean the area around the hole down to bare metal in preparation for welding.

 



Step 4 - Center the new sensor mounting boss on the hole and weld in place using an Arc-welder or preferably a Mig-welder. Remember that you are welding to a thin steel exhaust component, not a battle ship and excessive power and heat is not needed.






Step 5 - Reinstall the exhaust into the vehicle, apply nickel anti-seize compound to the new sensor fitting threads, install the sensor and torque to specification (22 lb-ft / 30 Nm) then apply silicone dielectric grease to the sensor electrical connector pins and connect the sensor to the vehicle harness. Ensure that the connector and the wiring is properly secured preventing contact with the hot exhaust system or other moving parts under the vehicle.




Article and Images by Keith Browning and Jeff Eichen




Fuel System UV Dye-agnosis

Detecting and pinpointing fuel system leaks can be difficult and time consuming. Fuel being a fluid of light viscosity means that it can migrate quickly and mix with other fluids. This is especially true for fuel systems with components that are located inside an engine and hidden under covers. This means that finding these leaks and verifying repairs is very important to prevent repeat repairs and severe engine damage. Safety is also another consideration with regard to any fuel injection system and even more so with high pressure common rail fuel systems. Fuel spray under high pressure will easily penetrate human skin, even through many types of gloves and risking exposure must be avoided. Fuel injected into the skin can poison blood, cause flesh damage and infections resulting in removal of fingers and limbs or even cause death.

Adding ultra-violet tracer dye to fuel will help identify and pinpoint fuel leaks and help promote safety. Old-timers might recall a time when running a piece of cardboard or paper along fuel pumps, lines and injectors was a common method of locating leaks. Using dye and an ultra-violet lamp keeps your body at a safe distance during inspections.

Diagnostically speaking the use of tracer dye is by far superior than any other visual method because the dye is extremely visible even when a small leak is present. The following two photographs show two examples of tracer dye being used to diagnose fuel leaks on 6.4L Power Stroke diesel engines that have a high pressure common rail fuel system. In the first example a smaller, slow leak at the fuel inlet fitting that otherwise might not have been easy to find. The second example another injector is leaking at the upper body nut and is a fairly large leak that was fairly obvious to see with the naked eye yet difficult to be absolutely sure that it also was not just engine oil splashing off of the adjacent valve components.

To use, add one bottle of UV Tracer Dye to the fuel filter housing - secondary or engine mounted filter on multiple filter systems. Typically the bottles contain about 3-ounces and you need to be sure to use dye formulated for use with oil based fluids. NOT water based dyes (coolant) or refrigerant dye (air conditioning). Then prime the system and run the engine for about fie minutes to get the dye mixed with the fuel and circulating within the system. Shut the engine down and begin searching for external leaks with a UV lamp. For internal engine leaks access the components to be inspected then inspect with a UV lamp. On some engines with electric fuel pumps you may drain the engine oil and leave the drain plug out. Turn the fuel pump on with a scan tool capable of bi-directional control and wait to see fuel dripping from the crankcase. The presence of dye will simply confirm the fact that fuel is leaking... validating the need to access valve covers or pumps and continue inspecting. In some instances it may be necessary to run the engine while inspecting for leaks.

 

Piston Protrusion

Piston protrusion is a term that refers to how high a piston crown travels above the cylinder deck. There are several reasons for checking this specification but here we want to identify bent or twisted connecting rods. This 6.4L PSD engine has performance issues and low compression in two cylinders related to a failed common rail fuel injection system. The injectors in this engine have been known to stick open allowing excessive amounts of diesel fuel to enter the combustion chamber which can cause bent or twisted connecting rods that sometimes may not be easy to identify by visual inspection alone.Bent or twisted connecting rods can cause low compression and piston and cylinder wall damage. During the disassembly of any engine it is important to identify the cause of a failure as well as related damage. In this era where it is more common to repair damaged engines with remanufactured assemblies than it is to repair them with parts and make measurements, many technicians no longer acquire the necessary measuring tools. This test however requires a dial indicator which is still a commonly used measuring tool.With the cylinder heads off of the engine the cylinder block deck and the piston crowns need to be cleaned according to the proper procedures outlined in the service manual. For each piston, two measurements will be taken along the wrist pin axis and then averaged to obtain the actual piston protrusion.
Here is the procedure as outlined in the workshop manual:
Zero the Dial Indicator Gauge with Holding Fixture on the crankcase deck surface. Position the Dial Indicator Gauge tip on the piston head at the 3 or 9 o'clock position. Rotate the crankshaft to measure the maximum piston protrusion and record. Reposition the Dial Indicator Gauge tip onto the piston head at the opposite position. Rotate the crankshaft to measure the maximum piston protrusion and record. Average the 2 readings. If the average reading is lower than the specification, the piston is lower in the bore than it should be. This indicates a bent or twisted connecting rod.

6.0L ICP Sensor Failures

We still receive a lot of questions about oil leaks and driveability concerns related to ICP sensors on 2003 and early 2004 model year trucks with 6.0L PSD engines. The Injection Control Pressure (ICP) sensor is a three wire variable capacitance sensor that produces a linear analog voltage that indicates pressure. This sensor provides feedback to the PCM as it modulates the Injection Pressure Regulator (IPR) and also to the Fuel Injection Control Module (FICM) where it is used to correct injection timing. The ICP sensor is a part of the high pressure oil system that supplies high pressure oil to the fuel injectors. Prone to failure the ICP senor shown below has physically failed. It came from a running vehicle that was intermittently stalling at idle. When the technician tried to disconnect the sensor it simply came apart. As these sensors fail they typically provide erratic and biased signals which affect engine performance. The symptoms may include an illuminated check engine light, stalling, erratic idle, engine surging at all loads and speeds and no start conditions. It is very common for this style of ICP sensor to leak which is usually the first sign that it is failing.

 
Making matters worse is the damage oil causes to the engine harness. Shown below is the three pin ICP sensor connector. Aside from the fact that the oil does not belong there it wicks up into the harness where it causes the wiring insulation so soften, swell and even split as seen here. Notice the exposed wiring. This is the reason that many ICP sensor replacements also require a harness repair with a service connector pig-tail. Those of you with a keen experienced eye should have noticed that the connector here has already been replaced as evidenced by the same color insulation on all three wires. When performing the repair it is important to cut back into the harness to splice into wiring that is in good condition. Making sure that the harness is as oil free as possible and re-wrapping the harness with new conduit and tape will promote a lasting repair. It is equally important to clean as much oil from the heat shielding as possible before reassembly to avoid re-contaminating the wiring.

Working Clean

Taking care to protect engines and their components from contamination and damage is an important part of performing effective repairs and reducing additional and repeat failures. This means that as a technician you should always consider working clean and take reasonable steps to protect vital vehicle assemblies and systems from foreign objects, dirt and debris, water or cross contamination of fluids. The first thing to consider is your work environment. Are you working outdoors where there is a lot of dust in the air or where weather can be a factor? Even indoors we need to consider where work is being performed. Working near a wash bay or next to other technicians or equipment where dirt can be blown around for example are all possible sources of contamination.
Before beginning work that will open the engine or the fuel system inspect the engine and clean off any oil, dirt and road debris than can fall into the engine or components. Fuel systems require extreme care because even the smallest contamination can have serious affects. Removing dirt from connections also means cleaning off any paint chips that break off of fuel lines and fittings when using tools. It is recommended to use electrical contact cleaner for fuel system cleaning as it will leave no residue - residue that could be considered contamination as fuel system clearances are extremely close. Follow with compressed air and cap all fuel injector, fuel pump and fuel line connections immediately.

How you clean and the materials you use also require thought as some methods can introduce harmful abrasives that will damage bearing surfaces and other moving parts. Using aluminum oxide cleaning disks such as the popular 3M Roloc disks are one such source of this type of contamination. Scrubbing pads that can leave behind fibers. Wire wheels will leave behind small metal strands. The best options for scraping gasket materials is to use appropriate scrapers which include metal, brass and plastic types. Always plug oil, fuel and coolant passages. Tape off open areas or use other effective methods to prevent gasket and sealer material from getting into the engine.

There are many options to use for capping and covering. Pictured above is a collection of caps and plugs saved from new parts after installation. This is a great way to build up a collection so you always have a selection to chose from. There are also commercially available caps kits and most manufacturers supply them as special service tools. Remember to keep all of your caps clean as dirty caps and plugs defeat the purpose. Pictured below are some examples of special plugs, caps and covers however something as simple as masking tape or painters tape is quite effective.  

Clogged 6.7L EGR Coolers

EGR system concerns historically have plagued all modern diesel engines equipped with them in one way or another. Some failures have been extremely troublesome and even lead to catastrophic engine failures. Despite improvements in design and components one thing continues to be a problem. Carbon. In the 2011 Ford Power Stroke diesel engine EGR cooler cores are known to become restricted which is detected by the engine control software and will result in the Check Engine light being turned on and a DTC (Diagnostic Trouble Code) being set. While it is possible to find an issue with the EGR valve, Bypass valve or a sensor the cause is commonly caused by the cooler being restricted and sometimes completely clogged with carbon. For vehicle owners that have this problem with their trucks we thought it would be cool to show you what the cooler passages look like, both clogged and new cooler cores for comparison. (see image below)

We see this on random engines that seem to be running perfectly and a range of operating conditions so it is difficult to say what is causing this to happen on some trucks and not others. Mitigating carbon build up on the 6.7L takes the same approach as with it's predecessors. Use good clean fuel, repair any performance issues that can increase the amount of unburned fuel in the exhaust, ensure that your engine's software calibration is up to date, keep engine idling to a minimum and use a quality fuel additive that will boost the cetane rating of your fuel to help promote good ignition and more complete combustion.

As of now there is no known acceptable method of cleaning these EGR coolers and replacement of the core is necessary to correct the condition. This is not a cab off repair by any means and it is pretty straight forward. The only difficulty or possible problem that might occur is the bolts that attach the EGR supply pipe to the right exhaust manifold could seize and break during disassembly. Experienced technicians can usually sense when these bolts are going to be a problem and use methods to finesse the bolts loose but even then it can be a losing battle. The broken fasteners can sometimes be extracted but usually require drilling out with a thread repair insert required.
And that is all I have to say about that.


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