An EGR (Exhaust Gas Recirculation) valve is a component of the exhaust system in an internal combustion engine. Its purpose is to reintroduce a portion of the exhaust gases into the air intake system. This process reduces the combustion temperature and, consequently, the production of nitrogen oxides (NOx), a pollutant that contributes to smog and the greenhouse effect. By lowering NOx levels, the EGR valve helps meet environmental standards while improving engine efficiency and reducing harmful emissions.
To disassemble the EGR valve of a Peugeot 607, I had to remove or move some components, such as the air intake pipe, to create some space. Next, I disconnected several hoses and connectors attached to the EGR valve, carefully noting their positions for reassembly. Most of the nuts and bolts were located in tight spaces, making access difficult. Finally, I unplugged the electrical connector from the EGR valve before removing it from its location. I then removed the two screws holding the engine side and the other part together, allowing for a complete cleaning of the EGR valve as a whole.
After disassembling the EGR valves, I cleaned off the bulk of the deposits using Jexfour. I then finished the cleaning process with brake cleaner, carefully rinsing between each step to avoid mixing products. Before cleaning, the motor-controlled valve wouldn't move at all, even when applying reasonable force. After cleaning, it moved easily when pushed with a screwdriver and returned to its position without resistance.
Finally, I reassembled all the parts in the reverse order of disassembly. I first secured the EGR valve in place by tightening the nuts and bolts. Then, I ensured that each hose and connector was properly reconnected. I also reconnected the electrical plug and replaced the components I had to remove or move, such as the air intake pipe. Afterward, I checked to ensure everything was properly connected. Then, I refilled the coolant, using the bleed screws to release air from the system. To be sure everything was fine, I also checked the oil level. The oil level was too high, so I drained some to restore it to the correct level.
This DIY task was very interesting because the tight spaces forced me to find solutions on my own since such situations are generally not explained in manuals. By trying to manage on my own, I truly learned. I also had the chance to get a rough idea of how an EGR valve works. This taught me persistence since it took me a lot of time. The hoses were stuck due to age and had to be handled carefully to avoid damage, while some bolts were hard to remove because of their positioning. For example, one bolt was only accessible from underneath the car, and without a lift, it was challenging. As I couldn't see what I was doing for some bolts, I had to rely solely on my sense of touch.