# How do I check my spark plugs?



## farmerjohn1324 (Jul 28, 2015)

I used to get a error code that said cylinder 3 misfire. I no longer get that code, but I still feel my engine rumbling a lot and sometimes I can kind of hear a misfire. How do I check these?

2000 Chevy s10 4 cylinder.


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## LS-6 (Nov 26, 2019)

Remove them and if you haven't replaced them in a while it would be best to do so. They're relatively inexpensive but you need to gap them also if you're not familiar with changing plugs.
Even if the plugs you buy are "pre-gaped" still check the gap.


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## DexterII (Jul 14, 2010)

I lean toward trying to identify a particular problem before throwing parts at it, but, in this case, for the cost of set of a plugs and the fact that you would be taking the old ones out anyway, I would just go ahead and replace them and see where that takes you. And knowing that there is possibly a problem, I would probably do a compression check while I had them out just to have that part of the diagnosis done.


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## LS-6 (Nov 26, 2019)

I forgot to add since your vehicle is 20 years old the plug wires probably need replacing too since you have to pull them to check the plugs.
Start the engine at night when it's dark completely dark not under the street light or garage light ect. and pop the hood and look for small sparks/shorts along the plug wires. 

Let us know how things work out. :wink2:


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## farmerjohn1324 (Jul 28, 2015)

LS-6 said:


> I forgot to add since your vehicle is 20 years old the plug wires probably need replacing too since you have to pull them to check the plugs.
> Start the engine at night when it's dark completely dark not under the street light or garage light ect. and pop the hood and look for small sparks/shorts along the plug wires.
> 
> Let us know how things work out.


My headlights turn on automatically in the dark, so I don't think I can do that.


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## HotRodx10 (Aug 24, 2017)

> Even if the plugs you buy are "pre-gaped" still check the gap.



Only if you're using standard plugs. *If you upgrade to platinum, iridium, etc. don't put anything anywhere near the gap.*


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## HotRodx10 (Aug 24, 2017)

> My headlights turn on automatically in the dark, so I don't think I can do that.



I found this youtube video that shows you how to temporarily turn off the automatic headlights:








Short version - push the dome override 4 times in quick succession.


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## LS-6 (Nov 26, 2019)

farmerjohn1324 said:


> My headlights turn on automatically in the dark, so I don't think I can do that.


My 2003 S-10 has a button on the upper left of the lights if you cycle that twice headlights turn off.


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## huesmann (Aug 18, 2011)

And there's always unplugging the bulb connectors. :vs_laugh:

But seriously, if you can't figure out how to turn them off, you can always just hang a blanket over the front of the hood to get yourself enough darkness in the engine bay.


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## deamer1 (Oct 17, 2018)

I drive a 1995 chevy s10. I turn off the headlights for times like this by pressing the parking brake slightly a short distance. This shuts off the headlights. Pulling the release turns them back on.


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