EGR Valve Problems: Symptoms, Causes and Fixes

What the EGR valve does

The exhaust gas recirculation valve feeds a small amount of exhaust gas back into the engine intake. This lowers combustion temperatures and cuts nitrogen oxide emissions. It is fitted to almost all diesels and many petrol engines.

Because it handles exhaust gas, the valve and the passages around it gradually coat with carbon and soot.

Common symptoms

A sticking or blocked EGR valve can cause a rough or hunting idle, hesitation or flat spots when accelerating, a lack of power, more smoke than usual, higher fuel consumption and the engine management light. Some cars go into limp mode.

If the valve sticks open, the car may stall at idle. If it sticks shut, emissions rise and you may get a fault code even though the car feels normal.

Why they clog

Short journeys are again the main culprit. An engine that rarely gets fully warm produces more soot, and the carbon builds up faster. Diesel cars that do mostly town driving around Oldbury tend to see EGR and DPF problems together.

Clean or replace?

If the valve is mechanically sound and just carboned up, cleaning it and the surrounding passages can restore it. If the valve motor or position sensor has failed, it will need replacing. We run a diagnostic check and test the valve before recommending either, so you only pay for what the car actually needs.

Can I just block it off?

No. Disabling or blanking the EGR valve on a road car is not legal, can cause the car to fail its emissions test and may affect your insurance. We repair EGR systems properly so the car runs as the manufacturer intended.

EGR repairs in Oldbury

If you think your EGR valve is playing up, call us on 0121 544 3736. We will diagnose it and give you a clear quote before any work starts.