This article generally focuses on the operation and maintenance of the EGR valve, and especially in the case ford 2004 1.8 TDCI engine, but the same doctrines may also be applied to other diesel cars of the same age group. It should also be noted that all maintenance work is carried out under the car owner’s responsibility. The article contains facts, personal experiences, guesses, and direct lies, so the responsibility is transferred to the reader at this point. Be that as it may, the stuffy and smoking engine will give goosebumps during the annual inspection (at least in Finland), so you can continue reading on health grounds.

What is the EGR valve and its purpose?

The EGR valve aims to recycle some of the exhaust gases from the diesel motor back into the engine combustion chamber to reduce the temperature and oxygen level, thereby reducing nitrogen emissions (NOx) from the engine. The idea is beautiful, but it works only with new cars on laboratory test benches. In practice, the valve is the slow self-destruct mechanism of the engine, which increases smoking and reduces torque, especially at low RPM’s. Every installer who smokes knows what the engine is going through when the exhaust gas builds up with vaporized oil from the engine. The result is thick black tar, which gradually clogs the engine’s throat, limiting its fresh air. So, like a Malboro man, the engine starts to gust uphill.

Why maintain and what can one expect from maintenance?

After the “maintenance” of the EGR valve, an immediate decrease in smoke and restoration of motor power can be observed, like when people had quit cigarettes. Increased low RPM torque can be observed, especially with cars that are difficult to get moving without giving extra gas. After maintenance, a clutch can be lifted quite swiftly without the risk of engine exhaustion. Besides, according to my empirical research, the car’s smoking value decreased from 4.2 to 1.19, which can be considered excellent for such an old engine. Above all, with restored performance, the car’s service life increases with this small and easy operation.

How to maintain the EGR valve by blocking it?

Since EGR-valves are probably one of the most hated parts of diesel engines, maintaining such an instrument must pay particular attention to the valve’s final and thorough blocking. At its simplest, you can repair the EGR valve by yourself with a piece of sheet metal with two holes for two bolts. This tactically shaped plate is slipped between an exhaust manifold and the EGR connection tube (bronze colour in Figure 1) or between the valve and the connection tube. Given the engine compartment’s dimensions and the installer’s hand size, the more comfortable slit is found between the exhaust manifold and the connection tube, as shown in Figure 1. This flange joint also has a gasket that can be used as a template for the blocking plate.

Figure 1. Attachment of the EGR valve accordion tube (referred to as connection tube) to the exhaust manifold. The blocking plate is slipped between the flange joint shown in the figure. The casket under the flange joint can be used as a template for the blocking plate.

The blocking plate can be made from almost any piece of sheet metal, but here are a few things to consider. The material requires the durability characteristic of the metals and some form of corrosion resistance and formability. My blocking plate was made from a spatula purchased from Ikea, because of the “ingenious idea” that “stainless steel does not rust!”. However, when drilling holes, I suddenly recalled something mentioned in a vocational school for working with stainless steel. It can sometimes be quite challenging to drill a hole to a thin stainless steel plate, especially if you start with a dull drill and allow the material to heat up too much. That’s why it could a good idea to choose an affordable and ordinary structural steel which is easy to work with. Another aspect of material selection, in addition to machinability, is the tightness of the finished joint. The accordion tube attaches to the exhaust manifold with a flange connection whit the damper plate caught between the parts. It is known that stainless steel is quite stiff, so to ensure the tightness of the joint, the flange bolts must be tightened really tight. One could overcome this problem using a copper sheet that would seal the joint more easily been a much softer material.

The following illustrations show a couple of steps from the production of the blocking plate. The original seal was used as a template, and the shape of the seal was copied to sheet metal with a sharp spike.

Figure 2. Use the original seal as a template to copy the correct shape to the piece of sheet metal with a sharp spike. Mark also the holes. Traditional tools like shears, files and a drill, can be used for cutting the shape out.
Figure 3a. Like two berries. Note the absence of the middle hole from blocking plate.

Figure 3b. When the pieces are overlapping, the middle hole disappears.

The blocking plate is now ready! The piece can be finished with fine sanding paper. You can sand the sheet surfaces using a flat surface and water sanding paper attached directly to a flat piece of wood. Good surface finishing may improve the joint tightness.

Now the supposed reader is probably still here on the website reading the instructions, but if the reader had been working, the fresh blocking plate could now be placed between the flange joint described earlier. When servicing the EGR ventilator in this way, the EGR valve will continue to jam in peace(I meant that if it was jammed. This fix don’t jam the valve, only prohibited the exhaust gas entering the motor), without any feeling that the exhaust smoke is no longer available, and it sees no reason for the ignite a fault light.

Cleaning the intake manifold and the EGR valve

Once the EGR has been maintained, the intake manifold can be cleaned for extra performance. As discussed earlier, the EGR valve can slowly stuff up the whole intake manifold with tar restricting the airflow. So it would be a good idea to get rid of the old garbage and take the full advantage of the EGR maintenance. This step is easy, although it may seem unpleasant.
The intake manifold is sprayed with a cleaning spray designed to dissolve the accumulated junk, and letting the engine suck the dirt. But don’t worry, there it was going anyway. It is also possible to remove the intake manifold and clean it manually, which would save the engine from the mess, but when considering the old Ford in question…

The actual cleaning process goes like this; cut the motor intake pipe between EGR valve and air filter by removing suitable tubing element (I removed the rubber bend connected to the EGR valve), warm up the motor and spray the cleaner directly into the EGR valve according to the detergent instructions. In this car, the charge tube can be easily cut immediately above the EGR valve, which is probably the situation in other cars also. The undersigned used LiquiMoly Diesel Suction Channel Cleaning Spray for cleaning, which is available in Motonet (Maybe the best department store for motorist). Cheaper products are also sold for that purpose, but they were not on the shelf when making the purchase. Despite the price, LiquiMoly seemed to do his job, as the engine instantly rejuvenated ten years. After cleaning, put back the rubber bend and close the hood. When you are ready, you can drive around the block with high RPM’s to eliminate any remaining dirt.

The final outcome and other tips for reducing engine smoking

It is possible that the dramatic reduction in smoke was also affected by other factors in addition to maintaining the EGR valve since other means were also used to reduce the smoke. The used tricks were from the cheapest to the most expensive: driving four kilometres at 4,000 RPM before measurement approx. 2€, adding a Diesel 100 additive to the fuel approx. 5€ (ethanol should bring more oxygen to the fire event), adding STP race bred nozzle cleaner to the fuel for approx. 25€ and adding RVS additive to engine oil approx. 80€. However, it was clear that only after blocking the EGR valve and cleaning the intake manifold, the immediate benefit could be observed, leading to a conclusion that their superior effectiveness compared to other means was observed. Besides, clogging and cleaning is a fairly affordable solution costing only 12 – 27 € depending on the cleaning agent used, and assuming the blocking plate is free. See the following cost breakdown.

Chart by Visualizer

Finally, I would like to thank the Finish Ford Club group on Facebook, which gave me support in difficult times when my own EGR valve was dying.


Ps. Don’t be coy about leaving a comment if you want to rectify me or share your experiences. You can also ask about the topic or give better translations to specific words.


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