Mercedes-Benz Sprinter is a commercial vehicle because it is considered a passenger or cargo van. The EGR valve stands for the exhaust gas recirculation valve, which is part of modern combustion engines. The recirculation valve reduces the overall emissions to meet the safety standards. It controls the nitrogen oxide emission from the exhaust system, which is the byproduct of the combustion chamber.
Mercedes-Benz Sprinter EGR valve problems include stuck EGR valve, corrosion on EGR valve components, knocking sound, failure of the valve, and clogging of EGR valve.
Last week, I was driving this van to transport cargo from one place to another and faced the rough idling issue with higher fuel consumption. I thought it could come from the broken cylinder gaskets. I opened the hood to check them, which were free from cracks.
I called the mechanic, and he told me the issue came because of the failure of the EGR valve. Poor nitrogen oxide recirculation affected the combustion process and led to misfiring, rough idling, and difficulty starting the vehicle.
| Problems | Solutions |
| Stuck EGR valve | Carburetor cleaner |
| Corrosion of EGR valve components | Use EGR valve cleaner |
| Knocking sound | Replace EGR valve |
| Failure of valve | Check diaphragm movement |
| Clogged EGR valve | Clean the clogged EGR valve |
Stuck EGR valve
EGR valves cannot function properly when stuck in open or closed positions. A sticky valve cannot maintain the nitrogen oxide concentration moving toward the engine compartment.
The primary function of this component is to recirculate the nitrogen oxide in the exhaust system to reduce the overall emission, make the environment safe for people, and reduce greenhouse gas emissions.
Most modern vehicles, like the Mercedes-Benz Sprinter, are equipped with it to meet emission standards. These can get stuck in partially opened and closed positions, directly affecting the exhaust system and combustion chamber.
Sometimes, it gets stuck in the open position, and you can smell the fuel from the interior compartment because of the high hydrocarbon ratio.
You can also smell fuel from there because of unburned fuel in the exhaust system. Moreover, the check engine light also illuminates the cluster screen.
It also increases the fuel consumption and affects the overall fuel economy. It causes the excessive exhaust gasses to enter the engine.
The EGR valve gets stuck at a closed position, and exhaust gasses cannot enter the engine, which increases the engine temperature and causes the check light to illuminate.
Moreover, you can also hear the tapping and pinging noise from the engine compartment. The valve becomes sticky because of the electric or hydraulic system’s failure.
In addition, you can also face issues because of sludge and contaminants buildup on their surface.
The issue can come from the deposition of the soot particles on their parts. Moreover, faulty EGR control circuits also make the valve sticky.
Faulty or broken vacuum solenoid affect their smooth opening and closing according to engine temperature and exhaust gas concentration.
Furthermore, you cannot perform the smoke test because of the high concentration of hydrocarbons in the tailpipe of the exhaust system. It is necessary to check the vehicle’s electric system connected to the EGR valve. Moreover, you can replace the faulty solenoid with a new one to restore its smooth operation.
Many people prefer to clean it every 20k miles to decrease the chances of sticking. Unplug the valve from the exhaust system assembly for cleaning.
Cleaning after recommended mileage also increases the durability of this part. You can soak it in carburetor cleaner overnight and rub its surface with a brush to remove the grime and soot.
Corrosion of EGR valve components
Some of the EGR valve components are made of metal material. Corrosion can come on their metal parts because of moisture exposure.
Exhaust gas components come in exposure to unburned fuel, trace metals from engine parts, and unburned oil. Sulfur or sulfuric acid is the major constituent of these components.
It is acidic and causes erosion of EGR valve components in your Mercedes-Benz Sprinter. You cannot smoothly crank the engine to start your van.
Poor engine functioning can also disturb your overall routine and lead to costly repairs. In addition, condensation on exhaust components is common because of frequent high and low temperatures, which increase the chances of rusting valve parts.
You can also face issues because of their corroded connections. Remove the fastening screws to check the signs of damage and corrosion on their ports and other parts.
You can remove the corrosion by spraying the affected parts with EGR valve cleaner. Avoid spraying the solution directly on the electric connections and sensors.
Knocking sound
Many people complain about the knocking sound from the engine compartment because of the failure of the EGR valve. The issue usually arises when it gets stuck in open and closed positions.
My neighbor also faced the same issue in his Mercedes-Benz Sprinter passenger van. He heard the knocking sound while driving slowly and stopped to inspect the engine parts.
He did not ignore the issue and continued driving because of the risk of costly repairs. He told me he heard a knocking because of the overheated engine parts.
Knocking sounds usually come because of the overheated metal parts. He opened the hood, and the engine temperature was high, but he could not find the exact cause behind it.
He started driving and heard the same noise again. He called the expert mechanic to find the error codes in his vehicle. The mechanic told him the noise was coming because the faulty EGR valve was stuck in the closed position.
The higher nitrogen oxide concentration in the engine compartment is the main reason for the engine overheating. Excessive nitrogen also causes the pre-mature fuel ignition in the combustion chamber.
Moreover, engine temperature increases even at low rotations per minute because of the excessive nitrogen oxide in the exhaust system.
An EGR valve stuck at a closed position does not allow the recirculation of exhaust gasses. It is necessary to clean it with a specific cleaner or hire a mechanic for their replacement. Avoid touching engine parts until their temperature drops to normal because it can cause skin burns.
Failure of valve
The most significant problem of exhaust gas recirculation valves is their failure. The failed parts cannot remove and recirculate the nitrogen oxides from the exhaust system, which can lead to increased emissions.
You cannot comply with the emission standards because of the nitrogen oxide emission from the exhaust system’s tailpipe. The leading cause of their failure is carbon buildup from the exhaust system.
Carbon can accumulate on the intake passage of the EGR valve and cause it to get stuck at a closed or open position. Clogged tubes and exhaust channels also cause the failure of the plunger mechanism, which allows its smooth operation.
Moreover, clogged fuel filters, contaminated oil, and poor maintenance increase the risk of their failure. You should replace the clogged filters according to the certain mileage so contaminated fuel does not cause carbon accumulation on the exhaust gas recirculation valve.
You can check the failure of the valve from the diaphragm movement. Remove the vacuum hose and connect the valve to the hand vacuum pump.
Apply a small pressure to check the diaphragm movement. You have to replace the valve if the diaphragm does not move correctly because it is not holding the vacuum.
Clogged EGR valve
The EGR valve becomes faulty because of the clogging issue, which affects the plunger mechanism. It can get clogged because of the use of low-quality oil.
Low-quality oil has contaminants, which can deposit on the surface of these valves and cause problems. In addition, clogged fuel filters also block the inlet system in your Mercedes-Benz Sprinter.
You can clean the clogged EGR valve by removing the vacuum lines and disconnecting the electric connections. Remove the valve and soak it in a container filled with carburetor cleaner.
Related Articles: