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Keith Browning

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Everything posted by Keith Browning

  1. 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. This can be done by brazing just as effectively. 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
  2. 6.7L Block Heater Install

    The 2011 model year Super Duty brought us a new Ford Power Stroke Diesel engine. Engine block heaters and cords are still not standard equipment when ordered in all locations and owners of these trucks equipped with 6.7L PSD engines may want to add one. We have received requests for information about this topic so we thought it would be good to post an article showing where the heater element is installed on the engine and the proper routing for the cord. While this is not a terribly difficult procedure the how and where may cause confusion for some people. No problem! First, obtain the following OEM parts: Heater Element - Ford part # BC3Z-6A051-A Wire Assembly - Ford part # BC3Z-6B018-C Silicone Brake Caliper Grease and Dielectric Compound - Motorcraft part # XG-3-A Installation Instructions Step 1 - Drain the PRIMARY cooling system which is the rear radiator with the drain valve at the driver's side of the truck. Save the coolant in a clean drain pan or containers for re-use. Step 2 - Remove the right front wheel and tire assembly. Step 3 - Remove the right inner fender well to access the right side of the engine and frame rail. Step 4 - Locate and remove the cylinder block coolant drain plug just above the starter motor (below left) Step 5 - Install the engine block heater element and torque to 30 lb-ft. (below right) Step 6 - Apply the Dielectric Compound to the electrical connectors at both ends of the cord to prevent water entry and corrosion. The cord is also a 2-piece cord with a square in-line connector pictured on the right below. Apply the dielectric compound to that connection as well before installing the cord. Step 7 - Plug the cord into the block heater and place the cord along the top of the right frame rail and behind the suspension mount. The harness should drop down the inside of the right frame rail along the top of the oil cooler. Secure the nylon harness tabs at the points indicated below. Step 8 - Looking at the inside of right frame rail the cord runs along the top of the oil cooler and is secured with a nylon harness tab to the right front bumper bracket. Then from the front of the bumper secure the harness and 110V plug to the inside of the bumper with the nylon harness tab. Step 9 - Refill the cooling system and run engine and inspect for coolant leaks. Reinstall the inner fender well and wheel and tire assembly.
  3. 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. Example 1 Example 2
  4. 6.7L Turbo Fittings

    Engine oil and coolant leaks are not overly common on the 6.7L Power Stroke diesel engine however they are not immune. With there being a lot of components taking up real estate on the top end of the engine finding leaks can be a challenge. The quick connect fittings used on the Garrett turbocharger for lube oil and coolant are becoming somewhat of a pattern failure. Oil and coolant leaks that show up at the lower rear of the engine at the transmission converter housing more than likely originate up top. Both fittings are located at the top of the center housing of the turbo and a clear view of them is obstructed by the upper intake manifold. using a small mirror and a good light source may help you find leaks there or the use of a borescope may prove more effective. If there is any doubt remove the upper intake manifold to expose the turbocharger and to replace these fittings. The quick connect fittings are the similar for the coolant and the oil. Coolant leaks can be slow and will build up a lot of crust at the fitting. Oil leaks will usually be more of a seep but close inspection will reveal the source.
  5. Hunting Down Wiring Concerns

    Wiring harness concerns have been a part of automotive diagnostics since the beginning but cars and trucks are infinitely more complex now. Any technician can tell you that it goes with the territory. Ford trucks over the years have had their share of issues and over time we discover pattern failures and common areas where wiring faults tend to occur. On 2008 and newer Super Duty trucks one such area is located near the front left shock tower shown here. This is a location on the truck where a lot of the wiring is found because the battery junction box containing many of the fuses and relays for the vehicle is located there. Additionally this area of the truck is where many circuits pass through the firewall to the instrument panel. There are also several harnesses that continue down the left frame rail that contain circuits for many systems and components like the transmission, fuel system, exhaust aftertreatment systems, braking, and lighting to name a few. Any time you encounter faults that point to circuit faults pay close attention to the wiring in this area of the truck. In the pictures the inner wheel and splash shield have been removed to access the wiring for inspection and repairs. To the right is a close-up of the typical wiring damage caused by chafing you will likely find. Chafing can occur on the shock tower, the brackets mounted to the shock tower, the splash shield and even within the harness itself. Let's take a closer look. Point A This wire actually rubbed through on the edge of the plastic harness protective tubing. Wrapping the wires with electrical tape at the end and then to the protective tubing will prevent this from happening. Point B This wire was rubbing on the edge of the splash shield. Additional wires were rubbing there as well. Securing the harness away from known chafe points and limiting movement will prevent this from happening. Once the wire insulation is removed water and road salt cause the copper wire to corrode while continuing to chafe accelerating the failure. Repairing these circuits often requires cutting out a section of the circuit extending a few inches in either direction to eliminate corrosion that has spread inside of the insulation. Splicing in new wire and replacing the wire terminal at the hard shell connector is commonly required to make an effective long lasting repair. Always seal splices with adhesive lined heat shrink tubing that will prevent water from re-entering the wire causing repeat failures. When repairs are completed be sure to re-route and positively secure the harness away from the contact points that caused the failure in the first place.
  6. Going out of my mind with nothing but whacky problems and shit work!

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