Is Your Diesel Truck Running Rough? Schedule an Inspection of the EGR Valve

The exhaust gas recirculation (EGR) valve is an engine component that most diesel-truck drivers only discover when there's a problem - like that muscle you never knew you had until you took a long hike. EGR valve issues usually develop over time. When you finally notice performance issues related to the EGR valve, you must take action.
There are three things you should know about your EGR valve. A qualified diesel-engine repair shop can offer more assistance with your engine-cooling system, but this guide will get you started.

The EGR Is Part of the Cooling System

The EGR is a required part on modern vehicles. If your EGR valve isn't functioning properly, your truck won't pass emissions testing. That's because the EGR valve helps keep your engine cooler and cleaner than it would be without the valve.
EGR valves allow part of your truck's exhaust to go through combustion again. Some fuel remains in normal exhaust and becomes toxic when flowing out of the back end of your truck (or your stack). The additional combustion process helps burn that excess fuel up and reduce toxic emissions. The recirculated exhaust helps cool the engine, too.
The EGR valve is a vacuum-controlled device. It's directly attached to the exhaust manifold. Some people mechanically arrange the engine exhaust to bypass the valve when the EGR system has problems. This can lead to far worse problems down the line, including engine overheating and sludge buildup.
Signs of EGR-Valve Problems Are Easy to Spot
When you have EGR issues, you can easily mistake the problem for other parts failures. You may blame a bad batch of gas, a clogged air filter or a misfiring cylinder. EGR-valve problems mimic combustion and air-flow issues with symptoms that include the following:
  • Dash warning light on
  • Rough idling
  • Jumping when accelerating
  • Stalling at slow speeds
  • Tapping or pinging noises in engine
  • Strong detonations in engine
Your truck may stall when warming up if the EGR valve is not functioning. You may think the fuel is cold when it's actually the gooey residue built up on the EGR valve that's causing your truck to stall out. Carbon builds up inside the EGR valve quite easily, especially if you do a lot of in-town driving. When your diesel truck stops and starts frequently, it never gets a chance to burn off the carbon.
Carbon deposits are sticky and thick. They can completely block an EGR valve with a tarry resin that won't allow the valve to open and close properly. If too much carbon builds up, the valve may even break. Then, you have to replace the entire EGR-valve assembly.

Care and Maintenance of the EGR Valve

Have your mechanic check out your EGR valve with every oil change. Schedule a cleaning of the valve every year to keep your engine running smoothly. While the EGR valve is being cleaned, the EGR oil cooler and other components can get a good inspection as well.
The vacuum tubes attached to the EGR valve must be checked periodically. They can become detached, dry out or otherwise develop weak spots and leaks. The EGR valve is also fitted with gaskets that can be damaged and leak. Your diesel mechanic knows how to spot and repair these issues.
Some people take a DIY approach to periodically cleaning their EGR valves. It's an extremely dirty job that requires specific tools to complete, although the actual cleaning itself does not take a long time. You do run the risk of damaging the EGR with vapors from cleaners or too-vigorous carbon removal, so it's a job best left to the experts whenever possible.
The diesel pros at Powerstroke Performance and Repair are happy to assist with your EGR system and all of your engine-cooling components to keep your truck running clean and smooth.