Why Does My Spark Plug Wire Keep Popping Out

Imagine finding out that your car suddenly has no ignition. As you attempt to find out what the issue is, you notice that your spark plug wire popped out for no reason.

Now, if you face this problem quite often, you might be thinking, why does my spark plug wire keep popping out? Well, as a veteran automotive mechanic, I can give you the simple answer to that question.

Spark plug wires pop out when it’s not firmly connected to the spark plug crimp tab. Plus, it might also occur because of dust or rust accumulation in the connection point between the spark plug and the wire.

To solve this, you simply have to use mechanical pliers to create a strong connection between the crimp tab and the wire. Or, consider cleaning out the dust from the spark plug from time to time.

Want to know more about this topic? Just follow my guide below.

Spark Plug Wire Keep Popping Out: Understand The Problem

First of all, you have to understand how a spark plug wire is connected to a spark plug. And you also have to know the main components of a spark plug to solve this issue. To do that, check out the image I provided below:

spark plug terminal nut

As you can see, every spark plug has a “terminal nut”. And this is the point where the spark plug wire connects to.

Check out the image below to understand the components of a spark plug wire:

components of a spark plug wire

In the image, you may notice that the spark plug wire has a point by the name “snap lock plug grip”. This is the component that connects to the “terminal nut” of the spark plug.

Now, the main reason why your spark plug wire keeps popping out from the spark plug is that the “large crimp tab” gets loosened. It happens because the wire jacket gets melted due to heat generation when the spark plug is active.

Consequently, the connection between the “crimp tab”  and the wire gets severed. As a result, the wire pops out.

Also Read : Can Bad Spark Plugs Cause Knock Sensor Code | All You Need To Know

Why Does This Problem Occur? (In Details With Solutions)

As you can see from my explanation above, the connection between the wire and the spark plug “crimp tab” can get severed due to heat generation. But why does this phenomenon occur?

Well, I found out a few reasons for that. Check out below:

1. Spark plug wire not installed properly:

The job of the spark plug is to create a spark. So, it naturally generates a huge amount of heat. And, if the spark plug wire and the crimp tab are not tightly connected, that heat can melt the wire jacket and cause the wire to be severed.


The only solution for this problem is to install the spark plug wire into the crimp tab tightly. To do that, you can use heavy-duty mechanical pliers.

2. The spark plug electrode is corroded:

Sometimes it just so occurs that the spark plug electrode is too old. As a result, it is corroded and gets bent. Consequently, it creates an unusual spark and causes the spark wire to pop out.


What causes spark plug electrodes to bend is mainly dust. So, if you don’t want your spark wire to pop out, you might have to clean out the dust and corrosion from the spark plug every 2 to 3 weeks.

3. The engine combustion has melted the spark plug wire:

The spark plug is connected to the engine cylinders very closely. You can check out the image below to have a clear understanding of this:

the engine cylinder

Now, since the spark plug is closely connected to the engine cylinder, it is impacted when combustion occurs in the engine cylinder. Moreover, this is what causes a spark plug to crack and the spark plug wire to pop out.


In this case, the solution is to get a new spark plug from a better brand and get it installed by a professional automotive mechanic.

Frequently Asked Questions

Still have questions regarding the spark plug wire popping out? Then check out this FAQ section.

1. What happens when the spark plug wire pops out?

If the spark plug wire pops out, the spark plug cannot get an electric connection. So, it cannot create a spark. That means your engine cannot ignite the fuel and start the combustion.

2. Is driving a car with a loose spark plug wire risky?

Yes, it is indeed highly risky to drive a car with a loose spark plug or spark plug wire. It’s because a loose spark plug wire can easily pop out anytime and cause the engine to stop working in the middle of the road.

3. What can I do to prevent this spark plug wire from popping out?

The best way to prevent your spark plug wire from popping out is to use a strong spark plug boot. Plus, you also have to make sure that the spark plug wire is tightly connected to the crimp tab.

4. Can a spark plug wire cause an accident when it’s popped out?

Yes, spark plug wire can indeed cause a massive electrical discharge and an accident. More specifically, the loose spark plug wire might touch the other components of the engine and discharge huge volts of electricity. In turn, it can cause huge damage to the engine.


Now that you’ve got a clear understanding of this query, why does my spark plug wire keep popping out? In short, it’s mostly because of a weak connection between the crimp tab and the spark plug wire.

Now, as you can already see, spark plugs popping out is a quite common problem that every car owner faces when their spark plugs get old. So, you should really check on your spark plugs and replace them in due time to prevent this issue.

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