See full version: Good Spark Plugs VS Bad With Photos; Examples
Spark plug wires can go bad independently of spark plugs and cause all the same issues like a bad spark plug including misfires and performance problems. Search diagnosing bad spark plug wires to see how to go about testing them and finding problems with your wires. [links]
After lots of use, the electrode part of the spark plug will naturally start to get smaller and smaller. This depends on the type of plug how fast it happens, but you can visually see it if the spark plug is particularly old. Here are some photos of what it looks like when a spark plug gaps change as compared to new properly gapped plugged.
Should I put anti-seize on spark plugs before installing? This depends on who you ask. You can read my entire post examining this question here, but what I believe from my research to be true is if you understand anti-seize and use it correctly you should apply it to spark plugs every time they are removed from an engine and installed. If you are a beginner with anti-seize remember these KEY concepts: anti-seize reduces friction on the threads of the spark plug making over-tightening the plug easier, you must only use a TINY amount of anti-seize and apply it only to the middle of the spark plug threads (do not get any near the electrode or the base), lastly, use only high-quality anti-seize (I prefer Nickel based anti-seize). [links]
That is why it is very important to always keep track of what spark plug came from what cylinder. You can mark them with a paint pen is the easiest way or lay them out in good order. more
Keep reading to see a ton of photos showing good spark plugs vs bad plugs. Hopefully, these will help you learn some of the more common telltale signs of bad spark plugs.
Can a bad spark plug cause engine knock? Yes, a bad spark plug can cause engine knock. So can a lot of other components on a car, but engine knock aka pinging or detonation happens when something is wrong with the ignition of the fuel-air mixture inside the cylinder. When a car is experiencing engine knocking you typically hear a “pinging” noise coming from the engine. Engine knocking can cause serious internal engine damage that is very costly to fix, so make sure to take your car in for service immediately if you are experiencing engine knocking. Engine knocking can be caused by using the improper spark plug for your vehicle. That is why I always recommend using OEM spark plugs. here
From my research, the two best kinds of anti-seize for general automotive use are the nickel and the aluminum variety
It is up to you to come up with your own technique and style. more
Here is what NGK says about anti-seize on Spark Plugs:
If you checked all the spark plug wires or coils and the same issue persists, spark plugs need to be checked. For this, there is no plug or unplug method but you have to remove the spark plug and carefully check for the following :
here
Your car will have different symptoms when having bad spark plugs. Sometimes the OBD reader, commonly known as the computer scanner will not detect bad spark plugs because of different variables. Bad spark plugs will cause your car not to start as fast. You might think that is a battery issue but late starts sometimes are caused by bad sparks.
Coils or Spark Plug Wires transfer the 12V electricity from the battery to the spark plug but with a much higher voltage that goes up to 60,000V to make the spark plugs fire. Sometimes these spark plug wires can get clogged up with oil or carbon deposits.
Swap The Coils
What is the best way to check bad spark plugs? Read this article and save yourself time and money.
The faulty plug wire symptoms are rough idle, bad starts and hesitation on acceleration. An easy process for you to determine is to swap the wires. The coils can be unscrewed after you remove the connector. You swap the coil that comes up as defective on the code reader with another coil that does not show any codes. If the error code for the bad coil will go away and transfer to the other cylinder you have a bad coil.
Autolite applies a nickel plating to the threads of new spark plugs that resist corrosion and seizing.
NGK spark plugs are manufactured with a trivalent plating. The spark plugs display a silver or chrome finish on the threads. The trivalent plating reduces corrosion resistance from moisture and chemicals. The trivalent coating also acts as a release agent during spark plug removal. NGK spark plugs should be installed DRY, WITHOUT anti-seize. [links]
That’s when spark plug manufacturers and carmakers started recommending the application of a small dab of anti-seize on spark plug threads. That way, the spark plug could be removed easily the next time. more
When carmakers switched to platinum-tipped spark plugs that lasted up to 100,000 miles, spark plugs started to seize in the cylinder heads. The problem got even worse as carmakers switched to aluminum cylinder heads. The dissimilar metals went through a galvanic reaction where metal transferred and welded the spark plugs to the head. When the DIYer or professional tech went to remove the spark plugs, they would often rip the threads right out of the cylinder head. more
Whoa dude, that’s WAY TOO much anti-seize here
shell distortion and combustion gas leaks and also spark plug thread damage in the cylinder head. [links]