EGR Removal Services Dronfield

EGR Removal Lincolnshire

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Many Cars Today Whether Petrol Or Diesel Have A Exhaust Gas Re-circulation Valve (EGR) Fitted To Them. This Can And Often Does Cause Problems! But We Can Help With Either A Carbon Clean Or Complete Removal

EGR stands for Exhaust Gas Recirculation and virtually all modern cars, petrol or diesel, employ this technique to control pollutants in the exhaust via an EGR valve. Some use what’s called ‘internal EGR’, where there is no EGR valve as such. Here we’re dealing with EGR valves that make up part of any ‘external EGR’ system. The principle applies to both petrol and diesel engines, though it’s the latter that generally are more complicated and, sadly, more likely to gum up and require cleaning or replacement. 

What is an EGR valve?

Exhaust Gas Recirculation is kind of self-explanatory, but it’s quite a complicated and sophisticated measure. Put simply, spent exhaust gasses are recirculated back into the inlet manifold to be used in combustion again. The reason for this is to reduce the production of harmful oxides of nitrogen (referred to as NOx) to keep the car within legal pollution limits. The recirculated exhaust gasses bring down the temperature of combustion, as NOx is produced at higher temperatures and pressures.

There are disadvantages to using EGR too, in terms of fuel economy, performance and, in the case of diesels, the increased production of soot and particulates, but the latest engines use a variety of clever electronic control strategies to minimise the downsides while making full use of the EGR system.

In the early years of EGR development, there were very simple passages between the inlet and exhaust manifolds, but these days we have far more sophisticated control systems – and at the heart of it all is the EGR valve.

These too have evolved in sophistication, from simple pneumatically operated ‘open or closed’ designs to electro-pneumatic operation that allow continuously adjustable levels of EGR, to the latest versions that are directly operated by the ECU (Engine Control Unit).

The latter set-up allows varying levels of EGR depending on operating conditions and uses a myriad of engine sensors to adapt, though this is all done on a software level. The EGR valve itself must be variable in its opening and quick to react to input. It also must be resistant to high temperatures and robust enough to operate in a dirty environment under a lot of vibration.

Modern diesel engines use an EGR cooler, which passes engine coolant through a heat exchanger to bring the temperature of the exhaust gas down further before allowing it into the combustion chamber.

Faulty EGR valve Symptoms:

While some EGR valve issues may actually be due to their control systems – wiring and pneumatics, etc. – most come about because the valve itself gets stuck open or closed due to build-up of soot particulates, carbon deposits and a sticky tar-like substance. A faulty EGR valve should cause an ‘engine check’ light to turn on,
as that’s used to inform the driver that something that affects the engine’s emissions is not working correctly.

The car then needs to be plugged into a diagnostic machine to obtain the correct fault code to ascertain that it is indeed the EGR valve causing the problem. An auto electrician should also be able to measure the voltage at the EGR valve using a multimeter to check if it’s working correctly