Common EGR Valve Stuck Closed Symptoms: What Are They?

EGR valves stuck closed are a disaster for cars of any model, as their fuel consumption, emission, and engine performance will be seriously compromised.

A smart driver must learn to recognize the EGR valve stuck closed symptoms early to save the situation before it worsens. And my guide aims to help you with that; keep scrolling for remedies!

What Are The EGR Valve Stuck Closed Symptoms? 

egr valve stuck closed symptoms

Raised temperatures inside the combustion chambers, poor car performance, frequent stalls, strong fuel smell, knocking engine noises, and more are clear symptoms of the EGR valves getting stuck.

Most are visual/physical indicators, meaning even beginners should recognize these signals at first glance.

Increased Temperatures

As the EGR valve is stuck closed, your car will experience a sudden and very dramatic temperature increase inside its combustion chamber, creating noticeable pinging and knocking.

Even a well-functioning EGR cooler cannot help bring down the heat!

This issue gets even more obvious when the car is cruising and accelerating – which, needless to say, is very dangerous, especially for cars equipped with turbochargers.

The constant combustion temperature exposure may cause them to seize, putting your vehicles in jeopardy.

Poor Car Performance

Degraded performance is only to be expected – whether the EGR valve is stuck closed or open.

Any slightest signal of incorrect function sends fluttering, erratic signals to the car’s computer, which naturally affects how your car operates.

Increased Fuel Consumptions

As the valve gets stuck, the optimal temperature within the chamber is destroyed, failing to burn the fuel at its recommended condition.

Hence, the fuel operates much less efficiently than usual, eating up lots of energy.

Frequent Stalls In Idle Position

Another issue your car has to face is the bothersome stalls during the engine’s idling periods.

After all, the EGR valve stuck closed forever means exhaust gases will get trapped there instead of being let out.

Smells of Fuel

Continuous exhaust gas flows inside the intake manifolds reduce the revs and hamper your fuel’s proper burning.

Consequently, the emitted hydrocarbon gasses from the car’s tailpipe also surge – and here is where the strong fuel smell comes from.

The Engine Management Lights Are Turned On

Any problem with your defective EGR valve (stuck position, malfunction, error, etc.) will activate the engine management lights.

However, for people with less higher-end car models, remember that the EGR valve usually takes some time to degrade before getting stuck/failing completely.

And too bad, these lights usually could not pick up the symptoms until what happened already happened.

Thus, remember to always look out for other EGR stuck closed symptoms mentioned in my list.

More Emissions Produced

Since the EGR valves take charge of the car’s emission management, more emissions will come out if the valves refuse to work.

As mentioned, due to the trapped, unburned fuel, you will see more hydrocarbon gasses emitting from the tailpipe.

Not to mention, the high temperatures within the combust chamber also pave the way for excessive NOx gas formation, further increasing the emission rates.

Engine Knocking

One should also brace himself for the constant knocking or grinding idle noises after the bad EGR valves get stuck in their closed position. 

The fuel ignites much earlier at lower RPM and high temperatures, after all – the causes of all those sounds and clicks.

Detonations are another issue to look out for, since a second, unnecessary ignition may occur right after your normal ignition.

More Particulate Matters Inside Exhaust Gas

As a follow-up of clogged EGR symptoms, there will naturally be a lot more unburned fuel and particulate pollutants slogging around the exhaust gasses.

One pretty obvious signal is the increase of black smoke/liquid coming out from your car’s exhaust pipe.

A few liquid drops can be put down to dirty condensations – but constant drips are another different story altogether.

How to Clean Your Faulty EGR Valves to Make Them Unstuck?

stuck closed egr valve symptoms

Two types of EGR valves can be spotted for modern cars: mechanical and electric. The latter requires a bit more caution, which is why I divide the cleaning guides into different halves.

Assess which EGR valve type you have and trace along with the below-given steps carefully: 

Cleaning Mechanical Valves

Step one. Wipe and Inspect Their Vacuum Hoses

Pull the vacuum hoses off, then inspect them closely for any signals of weak spots or cracks.

Clean the residual black carbon deposits with carburetor cleaner (preferably stored in spray cans) or pipe cleaners (for compacted/hardened unburnt carbon deposits) 

Step two. Check The Damage On The EGR Valves

Loosen the bolts that fasten the valve to your engine intake, then examine the gaskets lining your valve’s bottom plate.

No cracks of frays mean they can still be reused. If not, drive to an automobile shop to seek replacements.

Step three. Clean The Gas Entry Ports and Return Tube

Use a pipe cleaning brush (as small-bristled as possible, like a toothbrush or wire brush) and carburetor cleaners to clean all the carbon from the return tube and entry port.

The port is usually a small hole with spring-loaded pintles.

Impatient and exhausted just by looking at the excessive buildup of carbon particles on the valve? 

Just save yourself some time and just replace it with another valve. But if you are still confident in your cleaning skills, proceed.

Step four. Clean Out Your Entry Port

Do not mistake the entry ports for the gas entry ports, though they do sound almost identical.

The former is where the engine sensors (or the intake manifolds) connect the valve tube while EGR valves are shut off.

Step five. Reinstall Your EGR Valve

Make sure the vacuum diaphragms move freely, then reinstall/ reattach the valve, exhaust, and air intake hoses in order. And that’s it!

Cleaning Electronic Valves

Step one. Disconnect Your Battery Negative Cables

By doing so, no currents will flow through the automobile system, keeping short-circuit issues at bay.

Step two. Remove The Sensors and Bolts

Remove/disengage any electrical connection and sensor on the air hoses. Once done, loosen the valves and gasket bolts before removing them completely.

Check the gasket and hoses for any wear indicators; if there are any, replace them.

Step three. Spray The Hoses and Valves

Spray them with carburetor cleaners, and brush carbon build-up off the pintle hole and hoses.

Remember to leave the sensors and electrical connections out of the spraying process.

Still, if there are signals of corroded connectors, you may consider purchasing electronics cleaners and di-electric greases.

Step four. Reinstall and Reconnect The Parts

Now that the cleaning is done, reinstall the bolts and gaskets for the valves. Reconnect the sensors, electrical connections, and negative battery terminals in order.

Is It Okay to Drive With EGR Valve Problems? 

Technically, yes, since EGR valve failure does not bring any immediate impact to the engine components yet.

But leave them untreated for prolonged time, and you will start noticing very obvious symptoms of worsened speed efficiency and car performance (as mentioned in the symptom list above).

And not to mention, they are far from a positive influence on the environment; more harmful Nitrogen Oxide gas will be unleashed than ever before.

Our planet has already been suffering enough from excessive pollution and industrial waste; it does not need toxic car emissions to add further to the mess.

Can A Stuck EGR Valve Damage Engine? 

what happens when egr valve stuck closed

Yes. As indicated multiple times throughout my guide, stuck EGR valve symptoms involve severe power reduction, acceleration difficulties, and compromised fuel efficiency.

So even if you give zero F about the environment and decide to tolerate the harmful gases emissions, there are still tons of reasons to fix the closed EGR valve as soon as possible.

Conclusion

Always keep an out for the EGR valve stuck closed symptoms by paying attention to the car’s performance, mileage, emissions, and fuel smells.

A thorough cleaning session should free the broken EGR valve from its closed position. But in case it does not, seek professional help immediately.

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