Informational Guide

Can Bad Spark Plugs Cause Transmission Problems?

Can bad spark plugs cause transmission problems? We answer this question and more in this detailed guide.

Cleaning spark plugs is a great way to keep the engine running as it should. With proper maintenance, you can keep your vehicle in tip-top condition. Can bad spark plugs cause transmission problems? We evaluate what happens when spark plugs go bad. Do spark plugs affect the transmission? Let’s take a closer look.  

  • Oil In Combustion Chamber  
    If oil is leaking into the combustion chamber, it can create contamination on the spark plug tip. This oil on the end of the spark plug leads to premature failure. If you notice oil on the plugs, you need to replace them.  
  • Overheating  
    If the spark plug tip continues to get overheated, it will fail prematurely. Overheating happens when there’s a malfunction in the cooling system or pre-ignition occurs. On top of ruining the spark plugs, both of these conditions are also bad for the engine.  
  • Carbon Buildup  
    Black soot on the spark plug electrodes and insulator tip shows that it is carbon-fouled. When this happens, you will notice trouble starting the engine, misfiring conditions, decreased acceleration, and there might also be a Check Engine Light on.  
  • Improper Spark Plug Gap  
    The gap in the spark plug must be set to factory specifications to ensure proper operation. You can use a spark plug gap tool to double check the settings. If the gap isn’t correct, there will be additional stress, leading to premature failure.  
spark plugs

Can Bad Spark Plugs Cause Transmission Problems?

Can spark plugs affect transmission performance? No, the spark plugs are part of the engine and won’t affect the transmission. However, if the plugs are bad, you will notice a variety of engine performance issues. Because of the lower torque and misfiring situations, you might notice that the transmission isn’t able to shift normally. 

Can bad spark plugs make your transmission slip? No, because the spark plugs are not connected to the transmission. They are installed in the cylinders of the engine. So if you are noticing issues with the transmission, you probably aren't dealing with an issue with the spark plugs.  

There is no such thing as a 2013 Chevy spark transmission plug. You will not find plugs in the transmission. Therefore, the transmission isn’t going to act up when the plugs fail.  

Instead, bad spark plugs are going to lead to the following symptoms.  

Engine Misfiring 

If the engine is hesitating or misfiring, bad spark plugs might be to blame. When the spark plugs are operating as they should, the engine will run smoothly. However, faulty plugs lead to an interruption in the combustion process that affects performance.  

Starting Trouble 

When the plugs fail, it becomes more difficult to start the engine. You might think the car is low on fuel or the battery is dead, but it could be bad plugs instead. If the plugs can’t produce the spark needed to start combustion, you won’t be going anywhere.  

Increased Fuel Consumption 

If you are spending more time at the fuel station, it could indicate that the plugs are bad. Poor gas mileage occurs when the plugs get dirty or fouled. 

Lack of Acceleration 

It’s difficult for the engine to accelerate as it should when the plugs are bad. There won’t be an appropriate spark when the plug gets dirty, leading the car to feel sluggish.  

Uneven Idling 

The engine runs smoothly when the plugs work as they should. However, when they fail, the engine starts to run rough, especially while it is idling. You might think that the vehicle is vibrating when this happens.  

engine showing a spark plug

How To Prevent Spark Plugs From Going Bad? (Maintenance Tips)

You can prevent the spark plugs from going bad. Here are a few maintenance tips to follow. 

  1. 1
    Perform regular tune-ups. Check the service manual to find out how often the spark plugs should be replaced. In some cases, you might need to change them every 30,000 miles.  
  2. 2
    Choose the best spark plugs for your application. If you can afford to spend a little more, opt for platinum or iridium plugs.  
  3. 3
    If you are noticing any issues with engine performance, check the spark plugs right away. Bad spark plugs can cause the catalytic converter to fail. Replacing a catalytic converter is an expensive task you don’t want to deal with.  

People Also Ask (FAQs)

How soon can spark plugs go bad? 

Copper spark plugs are rated for around 30,000 miles. However, if you use platinum or iridium plugs, you might be able to go up to 100,000 miles without a replacement.  

How do I know if my spark plugs need changing? 

You will start to notice engine performance issues. If the engine is running sluggish, the fuel economy is dropping, or you are having trouble starting the engine, you want to have the spark plugs checked.  

Will check engine light come on for transmission problems? 

In some cases, the Check Engine Light will come on for certain transmission issues. If the light comes on, you can check the diagnostic trouble codes with an OBDII scanner

What causes an automatic transmission to jerk when shifting? 

The most common reason for jerking while shifting is due to contaminated fluid. Before you do anything else, try to perform a transmission fluid flush and see if that resolves the problem.  

How long will a transmission last after it starts slipping? 

The transmission isn’t made to last if you continue driving it while it is slipping. Instead, you want to stop driving it immediately and resolve the problem. If you fix what’s causing issues, you can get many more miles out of the powertrain.  


Bad spark plugs are not going to lead to transmission problems, but they will cause trouble with the engine. You want to change the spark plugs regularly to ensure the engine runs as it was intended. If your car has transmission issues, have them repaired immediately.