Steve takes a look at Exhaust Gas Recirculation Coolers.
Exhaust Gas Recirculation Coolers and valve or EGR for short has become a dreaded talking point for diesel car owners in recent years, so what are they, how do they go wrong, and how can you prevent your EGR from failing.
What is an EGR Cooler?
It's purpose is to cool the exhaust gasses by passing it through cool air similar to a radiator. After being cooled the exhaust gasses a recirculated to the engine to cool the cylinders this reducing stress on the head gasket and exhaust valves which ultimately reduces the nitrous oxide emissions on diesel engines.
Where Can I find the EGR Cooler
EGR coolers are located directly on the engine and connected to the exhaust system.
Does it go wrong?
The short answer is yes, and can do so in various ways.
1. The gaskets can fail causing exhaust leaks.
2. The EGR can become blocked with carbo depositsvwgich flow through it along nwith the gases thus preventing the gases to flow properly. This can then cause the engine to overheat.
3. Engine Management Light comes on detecting fault 1 or 2 or because the EGR has another issue which may have caused the engine into limp mode.
4. Poor fuel economy because the cooler can't work efficiently.
5. Poor throttle response, again because the EGR is blocked.
6. Loss of coolant.
7. White smoke from the exhaust.
Can it be cleaned?
Yes it can but be warned it's a tedious job, and no guarantee it will be 100% effective at resolving the issue. But could save you thousands of it does!
Is it easy to replace?
The replacement of a EGR is a time consuming job but can be done by an experienced DIYer. Alternatively a garage can replace your DPF but be warned, the bills can run well over £1000 dependent on manufacturer. There are EGR delete kits available but, be aware that removing the EGR completely is currently a grey area in law, and they could make this illegal similar to DPF removal due to potentially increased emissions. If it is found to affect your car emissions for the worse then this will void your insurance/MOT.