Can The EGR Valve Cause Starting Problems? How To Fix It


The EGR valve is an important part of your car’s emissions system. It helps reduce emissions and over time, this important part gets clogged up by carbon buildup. But, can the EGR valve cause starting problems? If yes, then how to fix it?

In this blog post, we will discuss whether or not the EGR valve can cause starting problems and how to fix them.

Can The EGR Valve Cause Starting Problems?

Can The EGR Valve Cause Starting Problems

Can the EGR valve cause starting problems? Yes. When an EGR valve gets stuck open, it lets air into the intake that the engine isn’t expecting. When that happens, there’s not enough fuel for the engine to burn and that can definitely cause starting problems. The amount of oxygen coming through the EGR valve is constantly changing when you first start up the car, so it’s difficult for the engine computer to compensate for a bad EGR valve.

The EGR valve is a crucial part of the emissions control system in many modern cars. Its job is to recirculate a portion of the exhaust gases back into the engine, where they can be burned again. This process helps to reduce emissions of harmful pollutants.

If your car turns over but does not start, open the hood to see if the belt and pulleys spin. If they do, that means that the starter is working properly and the EGR valve stuck open could be the problem.

Constantly being exposed to exhaust gases means that the EGR valve has a great chance of getting clogged by carbon deposits. When the EGR valve eventually gets clogged or goes bad, it can cause starting problems.

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The EGR is designed to circulate some of the exhaust gases back into the engine to burn at a later date. The engine computer dictates when and how much exhaust gases should be circulated back. So, the engine computer sends a signal to the EGR to open the solenoid and send a certain amount of exhaust gases back into the engine.

If the EGR valve is clogged or stuck open, it will either send too much or too little air into the engine and will throw off the air to fuel ratio, causing the engine not to start.

How To Fix an EGR Valve That Causes Starting Problems

Can The EGR Valve Cause Starting Problems

If your car is having starting problems, the EGR valve may be to blame. The EGR valve helps to reduce emissions, and when it is not working properly, your engine may not start up as easily. Here is how to fix an EGR valve that causes starting problems.

1. Required tools for the task

  1. 10-millimeter socket
  2. Carbon cleaner
  3. Q-tips
  4. Paper towel

2. Locate the EGR valve

Make sure that the engine is cold and then open the hood. The EGR valve is located in the exhaust system, between the exhaust manifold and the catalytic converter. It is attached to the intake manifold and has a tube that runs all the way to the exhaust manifold. However, if you are unable to locate the EGR valve, you can check the owner’s manual.

3. Remove the EGR valve

There are two types of EGR valves: vacuum operated and electronic operated. If your EGR valve is vacuum operated, you will see a vacuum line on top of it. If it’s electronic, you will see an electrical connector. In either case, disconnect the vacuum line or the electrical connector and set it aside.

Then, there are usually two bolts that hold the EGR valve. Remove the bolts using a 10-millimeter socket and set them aside. After you remove the bolts, you can now easily slide the EGR valve out.

4. Inspect the EGR port

When you remove the EGR valve from the EGR port, this allows you to look inside the EGR port. Perform a quick visual inspection and look for any carbon buildup inside the port. If there is carbon buildup, this will indicate that the EGR valve itself has carbon buildup inside and needs to be cleaned or replaced.

5. Test the EGR valve before cleaning it

The EGR valve on your vehicle might just be clogged and needs cleaning. Or, it can be bad and needs to be replaced. This is why it is best to test the EGR valve before actually spending time cleaning it. As I mentioned before, there are two types of EGR valves.

Vacuum operated EGR valve test

Can The EGR Valve Cause Starting Problems

On top of a vacuum-operated EGR valve, there is a diaphragm with a vacuum hose. The diaphragm sucks in and pulls the valve into an open position, allowing exhaust gasses to circulate into the engine to cool the cylinders. To test a vacuum-operated EGR valve, press on the diaphragm with your hands and see if the valve opens. You should be able to move the diaphragm with your hands. If not, then the EGR is seized and has to be replaced.

Another way you can test an EGR valve is to check if it can hold a vacuum. Press the diaphragm in and then close the vacuum line. If the EGR valve is working properly, the diaphragm should stay in the same position. If it comes back up while the vacuum line is closed, you need to replace the EGR valve.

Electronic operated EGR valve test

Can The EGR Valve Cause Starting Problems

The electronic EGR valves which are present on newer vehicles are operated by an electric motor. The engine computer dictates when the EGR valve should be open or closed, according to the specific needs of the engine.

It is a bit tricky to test an electronic operated EGR valve because you will need to connect it to a power source and watch if it opens and closes. That is why I just usually press down on the hole that the solenoid pulls in and out. It should be fairly easy to press it down and once you stop pushing, it should come back up.

6. Clean the EGR valve

If you have tested the EGR valve and it is not working, you should replace it. However, if the EGR valve passed the test, you can clean it and save a lot of money. In order to clean the EGR valve, you need to spray carbon cleaner. Just make sure not to spray any carbon cleaner directly into the electrical connector or the vacuum line. Otherwise, for every opening that you see, you can spray carbon cleaner.

Then, grab a Q-tip and clean the inside of the openings. Just be careful not to leave any cotton from the Q-tip inside the EGR valve. I reinforce the Q-tip with some paper towel which allows me to clean the insides even better.

Another method that I use when cleaning an EGR valve is after I spray the carbon cleaner, I open and close the EGR valve. Opening and closing the EGR valve, allows the carbon cleaner to travel inside the valve and clean it.

7. Reinstall the EGR valve

After you finish cleaning the EGR valve, it is time to reinstall it and test the vehicle. Reinstall the bolts that hold the EGR valve in place and attach the vacuum line or electrical connector. Then, try to start your vehicle.

If you had a faulty or dirty EGR valve that caused your vehicle not to start, after cleaning the EGR valve or replacing it, your vehicle should start.

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Hi there. I am a certified Automotive Service Excellence (ASE) mechanic since 2018 and a car detailer for 10 years.

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