How to "Read" your Spark Plugs | Goss' Garage

motorWeek is made possible by Thai Rak comm rockauto.com State Farm and WeatherTech you know back in the day cars had a lot of ignition parts that today don't even exist like spark plug wires but no matter how exotic or how mundane all cars still use spark plugs and spark plugs we're out now if you know how to read the spark plugs that you take out of your engine well you can determine the general condition of your engine now look at this spark plug we're looking right at the center and we see that the center electrode is noticeably wore in a way well that's normal wear nothing wrong with the engine there that's just too many miles on a set of spark plugs now the next one the end of the spark plug is black dry and dry is the key black dry and looking now that would indicate a rich mixture if it's only on one cylinder you probably have a leaky fuel injector if it's on more than one cylinder then you probably have an overall fuel control problem now this next one really really clean spotlessly clean cleaner than any of the other plugs in the engine that usually signifies that coolant is getting into that cylinder and it is cleaning steam cleaning the end of the spark plug all right next this is what we hope to see we have a little bit of discoloration the electrodes are worn evenly and everything is clean there are no deposits that is normal now here's one we don't want to see this is where the end of the spark plug has dry sandy now in texture not in color dry sandy looking deposits that have built up primarily on the outer electrode you look at that and say oh oh got some bad valve seals means oil is being sucked into the engine in an atomized state and it's usually coming around the valve seals or the valve guides the last one this is really a bad one the end of the plug is all gunked up and filled up with deposits and so on it's wet it's oily it's greasy looking that means that liquid oil is coming from the bottom of the engine either around or through the piston and you probably need major internal engine repairs so learn to read the spark plugs and you'll know a lot more about the general condition of your engine and if you have a question or a comment drop me a line right here at motorWeek [Music] [Music]

Channel: MotorWeek

Views: 819,151

Rating: 4.920711 out of 5

Keywords: MotorWeek, MW, car, truck, suv, cuv, crossover, auto, automobile, vehicle, motor trend, review, drive, first drive, video, spark plugs, maintenance, engine, oil, coolant, leak, head gasket, repair, fix, diy, fire

Id: lVCs5gWLUyI

Length: 3min 26sec (206 seconds)

Published: Thu Apr 04 2019

Reddit Comments

[u/j-dewitt]

Good info!