How to Test and Clean an EGR Valve

Updated: Jan. 22, 2024

Get that new-car purr back again after cleaning an EGR valve

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Rough idle? A good dousing with throttle body cleaner may be enough to restore your EGR valve to near-mint condition, transforming a harsh idle into a soothing hum.

Tools Required

  • 4-in-1 screwdriver
  • Rags
  • Shop vacuum
  • Socket/ratchet set

Materials Required

  • Cotton swabs
  • Disposable gloves
  • EGR gasket
  • Rust penetrant
  • Throttle body cleaner

Idling and stalling problems can really add stress to your daily commute. The most common culprit is carbon buildup on the throttle body, exhaust gas recirculation (EGR) valve and idle air control (IAC) valve. Here we’ll show you how to clean an EGR valve. This simple procedure can often bring an EGR valve back from the dead and restore a smooth idle. If the cleaning doesn’t work, you’ll have to replace the valve.

Project step-by-step (4)

Step 1

Where is the EGR Valve Located?

Refer to a shop manual to find the location of your EGR valve. If it’s fairly accessible, stop at an auto parts store and buy a new EGR gasket, a spray can of throttle body cleaner, and rust penetrant. Spray the EGR retaining bolts with rust penetrant and let them sit while you disconnect the electrical and vacuum lines from the valve (label the vacuum lines so you know which ports they came from). Then remove the retaining bolts and lift the EGR valve out of the engine compartment.

Step 2

Spray the valve

Place the valve on a bed of paper towels and tilt it so the cleaning solvent won’t drain into the electric solenoid or vacuum motor, which operates the metering rod—the solvent can damage those components.

Hold the EGR valve so the cleaning spray drips away from the electric solenoid and vacuum motor. Continue spraying until the parts are free of carbon buildup.

Spray on the valveTMB Studio

Step 3

Check the metering rod

Check for smooth operation of the metering rod by pushing it in and out with a screwdriver. It should slide smoothly and close completely in the port. If not, apply solvent to a cotton swab and clean the shaft and port.

Check with metering rodTMB Studio

Step 4

Install new gasket

Replace the EGR gasket as part of the cleaning procedure. Check the passage under the EGR valve to see if it’s clogged with carbon. If it is, gently chip out the carbon with a small screwdriver and vacuum it out with a shop vacuum. Then reinstall the EGR valve using the new gasket.

Install new gasketTMB Studio