What to look out for in a failing EGR valve?

The symptoms associated with EGR valve failure are similar to those of many other engine management components, and because of this EGR faults continue to be a source of headaches for many technicians. However, there are a few signs to look out for:

· Check engine light: as with most engine management components, a problem with the EGR valve may trigger the check engine light.

· Engine performance issues: if the valve is stuck open the vehicle’s air-fuel ratio will be disrupted causing engine performance issues such as reduced power, poor acceleration and rough idle. It may also produce turbo boost pressure leaks, causing the turbo to work harder.

· Increased NOx emissions: when the EGR valve remains shut, the resultant high temperatures in the combustion chamber will leave a lot of unburned fuel in the exhaust, leading to increased NOx emissions and reduced fuel efficiency.

· Engine knock: the higher temperatures and NOx may also result in increased detonation or knock, heard as knocking noises in the engine.