Exhaust gas cooler – EGR module MAN TGX Euro 6 – causes of faults

The MAN TGX Euro 6 truck tractor is one of the most popular cars not only on Polish roads. The Euro 6 emission regulations have strongly influenced the design of the engine. The engine of the car is equipped with a large EGR module, or otherwise known as an exhaust gas cooler. For the needs of OE, EGR exhaust coolers are manufactured by Modine, and the EGR valve, which is practically an integral part of the cooler, is manufactured by another company. The steering is done by a servomotor, controller, automatics, electronics, electronic controller – I’ve heard many, many names.

The construction itself is very simple. Exhaust gases through the open flaps of the EGR valve enter the exhaust gas cooler and, through a system of pipes in a shell-and-tube cooler surrounded by a cooling liquid, get out at a lower temperature to the exhaust system and partly to the turbine to participate in the combustion process again.
By design, the construction is very simple, easy and pleasant. It turns out, however, that it is a huge problem for car owners, mechanics and workshops.
I have been dealing with regeneration for 10 years, I managed to see a lot in the field of exhaust gas recirculation not only for MAN TGX Euro 5 but also for Scania, DAF and Mercedes. In this entry, however, I will focus on the recirculator used in the MAN TGX Euro 6. Of course, I have my thoughts on this design and the problems with it. I will try to explain below what else may be the cause of the EGR module failure and what is worth paying attention to.

Almost 100% replaceable EGR, it is simply replaced and that’s it, a few weeks later the situation repeats itself and the problem with the EGR appears again. When asked what else has been mentioned, I practically never get an answer “what” and when asked what caused the failure of your EGR module the first time – I will not surprise you – the answer is – it unsealed. No one asks why this happened, which caused the Modine EGR module to fail. Below in a dozen or so words I will try to describe so that you know what to pay attention to when you dismantle the damaged exhaust gas cooler, the MAN TGX Euro 6 recirculator.

The exhaust gas cooler, exhaust gas recirculation or EGR module for MAN TGX Euro 6 fails primarily when there is no coolant in it. Then there is a situation in which the exhaust gases passing through the insert, i.e. the shell and tube cooler, are not cooled down in any way because there is no cooling liquid in the Modine EGR module itself. Exhaust gases with a temperature of about 700 degrees Celsius, which have no way to cool down, lead to overheating of the radiator insert and its unsealing. Then the car “loses” coolant, may lose power and cause increased fuel consumption – but these are “delicate” symptoms compared to what the lack of coolant can cause to the entire engine. The effects of overheating can be seen at a glance. The EGR valve or the throttle or otherwise the flaps are discolored, as is the pipe system inside. This is a clear signal that the car has traveled a lot “without water”

The main symptoms of EGR damage are primarily loss of coolant fluid. The simplest assumptions are that if the loss is up to 8 liters per week, the high pressure cooler, supercharger or simply the air cooler used in this model, mounted underneath near the oil pan, has been damaged. If the loss of fluid exceeds the above-mentioned value, the jacket or the shell-and-tube cooler inside the EGR module has already been damaged. 


With this in mind, it is worth checking the high pressure cooler when replacing the recirculator. When the turbocharger fails, a characteristic white coating appears on the EGR module, slightly reminiscent of “popcorn” – photos below. 

A damaged turbine also contributes to the problems with Modine. Damage to the turbine causes oil to appear in the exhaust gas recirculation system. After removing the EGR MAN TGX Euro 6, you can see oil in the valve section, as in the pictures below. Oil getting into the exhaust gases increases their resistance to cooling by the liquid flowing around, which in turn causes: 


– Overheating of the cartridge and its unsealing

– Dirty exhaust stream in the valve section, which determines the pressure of the exhaust gases coming out of the EGR cooler 

In the case of this design of the MAN TGX Euro 6 EGR exhaust cooler, there can of course be more causes and reasons, and they can also occur simultaneously. The most annoying and most common case is a combination of failure – MAN high pressure cooler OE 51095007168  (loss of coolant in the system) and problems with the turbine. Below are sample photos, after which you can determine with almost 100% certainty the cause of the EGR module failure.

Another problem with this design is, or rather, the injectors No. 7 and 8. They often fail and just pour (Arcoore gives you the opportunity to regenerate them). The fuel in the combustion chamber does not burn out as it should and the gasoline itself appears in the exhaust gas recirculator and leads to its damage. There are cases that the flaps or the throttle or the EGR valve are the most damaged. With all these aspects in mind, it is worth seeing, searching and considering what is/was the cause of the failure. EGR replacement alone will not always give the intended result in the form of no errors or recurring problems with Modine to MAN TGX Euro 6. Today, of course, we recommend all our solutions, but we focus the most on the MAN TGX Euro 6 regenerated EGR recirculator with a new original throttle complete with a servomotor.  The offer also includes the original flaps, the original MAN TGX Euro 6 EGR valve

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