Over time, the shaft and valves become inundated with carbon accumulation a mixture of soot, oil vapor from blow by and other deposits and eventually suffers from sticking issues. When the valves stick open or closed, poor drivability, smoke, low power, rough idle and hesitation occur.
Navistar and Ford attempted to correct the sticking EGR valve issue on the 6. When the EGR valve seizes at or near the open position, the 6. When the EGR valve sticks at or near the closed position, a scan tool will pull up a P code. The general consensus in many 6. In fact, many EGR valves begin to stick within 20, miles.
Roughly percent of all EGR cooler failures are the result of a plugged oil cooler starving them of coolant, hence the reason we spotlighted the oil cooler as the 6. With a lack of coolant supply making it to the EGR cooler, its ability to drop the temperature of the exhaust gases that need to reenter the intake tract is reduced significantly.
Recirculating nitrogen oxide emission can substantially aid in the reduction of heat and pressure in the engine. In total it provides an excellent reduction in emissions, and most modern engines must use a system of recirculation to meet current emissions standards set by the US Environmental Protection Agency. Pump High Output Dodge Cummins 5. To meet certain emissions standards, it is necessary to reintroduce exhaust gases into the intake air in order to bring certain elements in the exhaust within levels set for that year of truck.
The cooler has engine coolant running through it and looks very much like a regular radiator or heater core. The exhaust gas passes through this small radiator and lowers the exhaust gas to a temperature that it is able to be introduced into the intake system at.
On the 6. And here we have the first hint of a problem; the exhaust gas is always in the egr cooler. What goes wrong with this system and how can it hurt my engine? The big problem here is heat. It is possible for a completely stock engine to produce exhaust gas temperatures well in excess of degrees. So imagine taking degree air and constantly running it through your heater core day after day.
How long do you think it would last? Next, put that heater core in an enclosed box that has to endure not only the high temperatures, but also psi of exhaust backpressure that is built before the turbo between it and the exhaust manifold. Even though the cooler is made out of materials that are meant for higher temperatures, it is not a matter of if, but when your cooler will fail.
Best case scenario is that the cooler just leaks a little coolant into the exhaust system and it passes out the exhaust and you just notice some coolant loss.
Worst case scenario, exhaust pressure is able to enter a break in the cooler and enter the coolant system which only runs at 12 or so psi max. The high pressure will ruin head gaskets and oil coolers. Also, the coolant system cannot keep the truck cool with that much pressure in the system. This is why you will hear about or may have experienced coolant puking out of the filler cap on the degas bottle after pulling a load up a long hill.
The cap is made to bleed off pressure above psi. The increased coolant temp and extra pressure being pushed in from the exhaust will push coolant right out the cap. We have a truck in the shop right now with a blown egr cooler and head gasket. While failure to service your oil properly can lead to multiple issues with the 6. To make my case that Ford failed to produce and implement a quality EGR system, I will simply point out that on the 6.
While the design flaw discussed above is the result of the interior components of the later model 6. This electric motor valve is basically the same one used in GM gasoline engines and is operated by the PCM. The valve does have some trouble with soot buildup however.
Given that the use of any EGR in diesel engines creates a soot rich environment, we have to learn to mitigate the problems it causes. Ford recommends running cetane booster in your fuel and that does seem to help some. Actually, I would recommend running cetane boost regularly because it helps with more than just soot build up: since it is basically impossible to get quality diesel fuel from fuel stations nowadays and because diesel is known for water build up anyway, cetane boost in your diesel fuel can avoid a multitude of issues.
Cetane boost reduces idle timing in an EGR-equipped diesel and also keeps the water in your fuel in suspension so that it will be less likely to take out expensive fuel injectors.
If you store your truck, cetane boost is very important. Once you have the EGR valve removed, you should look for both the amount of soot build up and the kind of soot build up. Dry, dusty soot is usually a sign of normal EGR operation and not a threat to the engine. It can, however, get thick and may eventually get thick enough to cause the valve to hang open sometimes this will not register on a scan. While this may seem a design flaw, it is really part of living with the high soot and will, sooner or later, have to be dealt with.
I have sometimes gotten away with cleaning dust-covered EGR valves really well with some carb or brake cleaner. While dry soot is part of the normal operation of the EGR system, wet soot is another story. If you have an EGR valve is covered with wet soot, it means that there will be wet soot down in the intake as well. This is an indication of some type of engine concern.
If the engine oil is at the normal level, it could also be a sign of a EGR cooler that is beginning to leak. Another possibility may be an internal turbo issue that is allowing motor oil to leak past its seals into the intake. If this is the case, you can get a Center Housing Rotating Assembly from a Ford dealer and rebuild your 6.
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