Why do diesel motorbikes need to periodically clean the exhaust gas recirculation valve?

The EGR (exhausted gas recirculation) valve is dirty, causing the car to emit more smoke and consume more fuel than normal.

Reader La Van Cuong (My Duc district, Hanoi ) asked: The manufacturer's user manual recommends that diesel motorbike users need to clean the exhaust gas recirculation (EGR) valve periodically every 40,000 kilometers. Please advise what is the function of this part and why does it need to be cleaned periodically?

Technical consultant Le Van Dinh, Auto749 garage (Phuc Dien street, Nam Tu Liem, Hanoi) advises as follows:

The EGR valve (exhausted gas recirculation) is a part that opens and closes to bring part of the exhaust gas back into the combustion chamber during engine operation.

Using an EGR valve helps to divert 5 - 15% of exhaust gas back to the intake manifold, helping to reduce the amount of toxic NOx gas released into the environment.

In addition to reducing NOx, the EGR system also significantly reduces noise in diesel engines and reduces fuel consumption in some gasoline engines.

The EGR valve is normally closed and only opens when the vehicle is running at constant speed (on the highway) with a light load.

Therefore, if you often drive in the city, the EGR valve on diesel vehicles will quickly accumulate black soot and dirt more than vehicles that often drive on the highway.

At that time, the EGR valve appears to be clogged due to carbon deposits from soot. If not treated, it can cause engine weakness and fuel consumption.

Dirt build-up also causes two types of valve jams.

EGR valve stuck in open position: Exhaust gas is always brought back into the combustion chamber, taking the place of fresh air intake into the engine, causing the engine to be weak, slow to accelerate, emitting a lot of black smoke, wasting fuel, and the vehicle vibrating at low rpm.

EGR valve stuck in closed position: engine runs hotter, engine makes knocking sound when running, can cause loss of engine lubricating oil.

Therefore, the manufacturer recommends cleaning the EGR valve every 40,000km, however, if you often drive in the city and change the accelerator pedal at low speeds, the owner should clean this part at 30,000km.

Source: https://xe.baogiaothong.vn/vi-sao-xe-may-dau-can-dinh-ky-ve-sinh-van-tuan-hoan-khi-xa-192231201213423106.htm