How EGR Valve Cleaning Can Stop Stalling and Idling Problems

Get that new-car purr back again

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.

By the DIY experts of The Family Handyman Magazine

Remove and clean the valve

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. In this article, 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.

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.

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. Spray the port and metering rod until they’re clean (wear eye protection and gloves). Once the parts are clean, check for smooth metering rod operation by forcing the rod in and out of the port 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 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.

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

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

You may also need a small flat screwdriver for scrapping carbon deposits.

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

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

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