EGR Problems on Diesels: Causes, Symptoms & Fixes

The EGR (Exhaust Gas Recirculation) valve is a common source of diesel headaches. Here's what it does, why it fails, and how we sort it.

What the EGR does

The EGR recirculates a portion of exhaust gas back into the intake to lower combustion temperatures and emissions. The problem: over time that soot-laden gas clogs the valve and intake with carbon.

Symptoms of a failing EGR

• Engine management light or limp mode
• Rough idle, hesitation or lumpy running
• Loss of power and poor economy
• Excess smoke

How we fix it

First we diagnose properly — sometimes it's a cleaning, sometimes a faulty valve to replace. Where appropriate (for off-road, motorsport or export use), an EGR solution resolves recurring faults. We'll always tell you the right fix for your car rather than the quickest.

Got an EGR fault or warning light? Get in touch and we'll diagnose it. See also our guide to DPF problems.