A modern car is a very complicated mechanism, which is debugged by engineers at the factory. Every year more and more units and assemblies appear on the car, about the existence of which we could not assume 20-30 years ago.
Environmental background for EGR
Most changes are made to the design only for safety reasons. Somebody can tell. That this is an incorrect wording… However, we should not forget that in addition to active and passive safety, there is safety and the environment.
Car manufacturers constantly swear to environmentalists, the so-called “green”, for lobbying for tougher environmental requirements for cars, at least that’s how they try to present it.
In fact, things are a little different, namely the manufacturers themselves raise the bait and sponsor environmentalists in order to justify the increase in prices for cars and say.
The scheme has been worked out for years:
- manufacturers sponsor environmentalists (to tighten environmental standards);
- environmentalists, then they oblige the factories to follow the standards. By means of “suffocation” of engines, use of catalytic converters, electronic gas pedals and other labouda;
- manufacturers increase the final price of cars, justifying this by stricter environmental regulations, which require costly structural changes;
- the buyer pays money for “incomprehensible improvements” that do not add comfort and gloss, reduce dynamic performance, etc.
Appointment and operation principle
EGR is an English abbreviation for Exhaust Gas Recirculation, which can be translated as “exhaust gas regulation system”. This system periodically sends part of the exhaust gas back into the intake manifold to form a new portion of the mixture.
The system has the following functions:
- It provides a more complete combustion of the working mixture, thus reducing toxicity.
- Heats up the vehicle’s power system faster (e.g. intake manifold).
As you know, the engine exhaust temperature reaches several hundred degrees, so the EGR valve, which is in direct contact with them, is made of high-alloy steel. Naturally operating in such harsh conditions, the EGR valve cannot boast a high service life.
The main purpose of the valve is to reduce the concentration of nitrogen oxide in combustion gases of combustion engines – this is achieved by reducing the oxygen content in the working mixture fed into the cylinders. The EGR valve directly redirects part of the flue gases, in which oxygen almost all burnt when the working mixture is ignited in the cylinders, but to small amounts is still present in the inlet manifold.
As a result, we get a decrease in the concentration of oxygen in the intake path, respectively, the process of combustion of the working mixture (air + fuel) runs at lower temperatures. Not going deep into the chemistry course, we get a decrease in nitrogen oxide emissions.
Naturally, reducing the concentration of oxygen in the working mixture, we thus impoverish it, which negatively affects the engine power characteristics. But, these are the environmental requirements…
- Pneumomechanical. Nowadays it is extremely rare, as cars equipped with it are more than 20 years old.
- Electropneumatic. It was installed on cars that meet environmental standards EURO 2 and 3. There are 2 valves responsible for the recirculation process. Pneumatic valve is responsible for opening and closing the inlet nozzle of the burnt-out working mixture into the inlet manifold. The solenoid is responsible for creating the discharge required for the operation of the pneumatic damper.
- Fully electronic or as it is also called “digital”. It can be found on cars according to EURO 4, 5 and 6 standards. It is controlled directly by signals from the electronic control unit. In contrast to the previous one, it has intermediate positions in addition to the “open” and “close” positions.
- Clogging may cause the valve to jam during operation or increase the opening/closing time. Signs of clogging may include: reduced engine power, “floating” idle speed, increased detonation and increased fuel consumption.
- An EGR valve that does not close completely will result in a more noticeable power loss.
- The consequence of a valve failure is a failure of the entire exhaust gas regulation system, which is accompanied by a light flap on the dashboard, at the head of which the check engine lights up. The signs of this are usually: “floating” idle speed; smoke from the exhaust pipe; reduced power of the combustion engine; detonation and more noisy operation of the power unit.
For cleaning we will need: a set of wrenches (you may even need a socket wrench) and screwdrivers, carburetor cleaner, rags and thread sealant. It will also be necessary to determine the type of valve installed (see the text of the article above): pneumatically necessary to clean the seat and rod, and electric – a filter that protects the vacuum chamber from foreign objects.
Removal of the valve and its plug
Possible advantages of the plug:
- A longer service life of the engine oil and therefore a longer interval between changes;
- Improved traction and speed characteristics of the car;
- No need for repair or even worse, replacement of the defective valve (saving money);
- Combustion products of the working mixture do not get into the inlet manifold and therefore do not contaminate it.
If you want to jam it, here are the possible consequences:
- nitrogen oxide emissions are increasing;
- decreases the life of the catalytic converter;
- increased fuel consumption;
- occurrence of detonation (typical for gasoline combustion engines).
Of course it’s up to you to clean up the EGR system or not. But look at the possible consequences of operating without EGR: a burned lambda probe, a clogged and then cut out catalyst, clogged fuel injectors.
If the GHG recirculation system is functioning properly, you don’t have to interfere with its operation under the pretext of increasing engine power. If a malfunction occurs, the option of plugging or removing the system can be considered, but with consideration of the possible consequences.