Navistar’s Maxxforce engines can be found in many heavy-duty vehicles, with International trucks lineup being one of the biggest. This revolutionary big bore engine was designed to be superior in every category. It excels in efficiency, durability and drivability. When compared to other engines, it is not only more powerful. It is also lighter, stronger and more durable, all thanks to a compacted graphite iron cylinder block. And, as it features advanced emission control technology, EPA regulations are met without the need for DEF fluids. All of this makes it perfect for commercial use. In theory, at least.
However, as these trucks started racking up miles, several problems have surfaced. Although generally reliable, a Maxxforce engines are known to have a number of emission control related problems. And Exhaust Gas Recirculation system issues take the top spot. This is due to the problems such as carbon build-up or cooler matrix leakage. In extreme cases, EGR failure can cause irreversible engine damage. On top of all that, repairs are quite expensive. Let’s look at several prices:
- Cooler repair set
- Uprated heater core
- Includes all gaskets, seals, and hardware for installation
- Considerably lower price
- One Year, One Million Mile Replacement Warranty
- Direct replacement module
- Heavy-duty heater core
- Installation gasket kit is included
- One Year, One Million Mile Replacement Warranty
With all these problems, it is only natural for truck owners to consider some alternative solutions. One of the most popular options is called EGR delete, which completely shuts down the system. Physical part of the process involves installation of steel blocking plates into the EGR cooler. This prevents any exhaust flow towards the intake. The other part of the process is a bit more tricky, as the electronic computer unit needs to be reprogrammed. This is done by a specialist who opens and flashes the ECU. By eliminating this troublesome system truck owner will end up with a truck that is a bit more reliable. This might be considered as a victimless crime, right? Well, it’s not that simple. There are a several reasons why the EGR system should not be removed:
- it is illegal. With strict regulation about emission control and inspections, a truck with deleted EGR system will have a hard time passing a smoke test. And in worse case scenario, a truck owner might end up with a steep ticket.
- it is very harmful for the environment. And it is not just about the trees or polar bears. Excessive amounts of soot, carbon monoxide or nitrogen oxides can have serious health impact.
- Lastly, it may be very damaging to the engine, as it was designed to work with charge air that contains a certain amount of exhaust gases. Elimination will lead to higher combustion temperatures, which can have a irreversible impact on the engine internal parts.
So what can you do to avoid the dreaded EGR problems? First of all, get this system running correctly. If some components are not working correctly, replace them. Also, as prevention being the best cure, make sure you follow these guidelines:
- Use only high-quality fuel, as this reduce amount of soot
- Don’t skip engine oil changes
- Be careful not to overfill the engine oil
- Use correct grade of engine oil
- Check the crankcase ventilation system for blockage
- Perform regular maintenance
Why is EGR used?
Modern diesel engines have several advantages, with low fuel consumption being just one of them. Development of variable turbochargers and sophisticated fuel injection systems enabled wide torque range and faster throttle response are achieved.
As a result, diesel powered vehicles offer strong pull from low revs and smooth drive. This makes them ideal for heavy duty applications. You will find diesel engines in many big pick-up trucks, as well as in most trucks and buses. Still, there are several downsides, with higher amount of harmful pollutant in exhaust gases being one of them. Compared to a gasoline engine, not only it will produce more nitrogen oxides or carbon monoxide, but it also produces far more soot.
To make things worse, trucks and buses usually do more miles than cars, thus emitting higher amounts of exhaust gases. This makes diesel powered vehicles a big part of overall air pollution. Although this problem was largely ignored in the past, things have changed. Emission control systems have become one of the main concerns in engine development over last ten years.
Every few years, new government regulations increasingly demands reduction harmful pollutant emissions. In most cases, the emphasis is on the amount of nitrogen oxide and soot produced by diesel engines. This means that vehicle manufacturers are forced to install more and more complex devices and systems to meet those regulations.
There are several ways to reduce emissions. Diesel Particle Filters, or DPF, are used to eliminate soot, but they don’t do anything about the NOx. This is where either SCR (Selective Catalytic Reduction) or EGR (Exhaust Gas Recirculation) come into play. While Selective Catalytic Reduction system is a more simple solution of the two, it still has some downsides. Not only that it requires one additional fluid to be regularly filled up, but also this DEF fluid can freeze and crystallize during cold winters.
Exhaust Gas Recirculation system, on the other hand, is a self-sufficient system that does not need any intervention from the driver. This system has been used in cars for decades. And, being relatively simple, they rarely cause problems or costly repairs. Still, situation is a bit different when it comes to big truck engines. Unlike car system that only have few pipes and a control valve, EGR systems on heavy-duty engines are a bit more complex. Main difference is the additional cooler, which lowers the exhaust gas temperature before it is mixed with intake air.
As the cooling core is very dense, oil vapors, poor engine combustion or unfavorable driving style can cause the formation of carbon deposits. As a result, exhaust flow will be obstructed. In most cases, this can be cured by using strong EGR cleaners if it is done on time. Other possible problem is a coolant leak caused by a broken cooling core, which can cause engine overheating or even a hydrolock. This is something where only a new cooler core will help.