spark Plugs - detonation - Photo 9221898

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Problem: Detonation<BR />Here you can see how this form of abnormal combustion has damaged the insulator core nose of the plug. Causes can include a faulty EGR valve, ignition timing advanced too far, lean air/fuel mixture, or low gasoline octane rating.

Problem: None<BR />Here you can see a normal used spark plug. Note how the combustion deposits are slight, and they won't have any effect on engine performance. The plug has a brown to grayish-tan color, indicating that the plug is in the correct heat range and operating in a healthy engine.

Problem: Bridging<BR />This rarely occurs in engines used on-road. During aggressive off-highway driving, combustion deposits can be literally thrown loose and then they may lodge between the electrodes. Another cause of bridging is when fluffy materials that accumulate on the side electrode melt and bridge the gap when the engine is suddenly put under heavy load. Both conditions may result in a dead short or misfire.

Problem: Excessive wear<BR />This plug is worn out. Note how both electrodes are showing extreme wear, thereby creating a huge gap. Naturally, this large gap will affect how the plug performs. The voltage required to fire a plug like this has effectively doubled and will continue to increase the longer the engine operates. Further, even higher voltage requirements may occur when the engine is accelerated quickly. Expect poor engine performance and a loss of fuel mileage.

Problem: Carbon fouled<BR />Marked by a soft, sooty carbon deposit. If all of the plugs are carbon-fouled, the plugs may be too low of a heat range; the air/fuel mixture may be too rich; the air filter may be dirty; or you may have a weak ignition, a sticking heat-riser valve, faulty choke or bad fuel injectors. If the problem is limited to a couple of plugs in a set, look for sticking valves, a cracked distributor cap, or bad plug wires.

Problem: Thermal Overload<BR />Matt Hallis, Product and Technical Support Manager at Bosch Corporation, says that this can be caused by using a plug that is too hot or by an overly lean air/fuel mixture (like a fuel management, intake manifold, or O2 sensor problem). Surprisingly, Hallis said that another cause can be insufficient spark-plug torque. Since one of the spark plug's duties is to conduct heat away from the combustion chamber, if a plug isn't tight it can't accomplish this goal.

Problem: Carbon flashoverThe folks at Bosch tell us that when this happens, the spark can jump from the electrode to the side of the plug, causing a misfire. One of its causes could be an overly rich fuel mixture or possibly too much fuel pressure.

Problem: Improper gap<BR />This gap between the electrodes is far too small for the plug to create the proper spark kernel and ignite the air/fuel mixture. The result will be poor performance and unburned fuel.

Problem: Detonation<BR />Here you can see how this form of abnormal combustion has damaged the insulator core nose of the plug. Causes can include a faulty EGR valve, ignition timing advanced too far, lean air/fuel mixture, or low gasoline octane rating.

This is the business end of a Platinum+4 spark plug. As you can see, it sports four electrodes to provide optimum access to the air/fuel mixture. Bosch says this results in the most efficient combustion, and it also contributes to a longer performance life. The electrode gap is factory set, so you just screw 'em in.

In addition to performance, Bosch says that the Platinum+4 can also help improve fuel economy. This Bosch chart shows up to a 4.8 percent increase in fuel mileage when compared to a standard plug.

E3 supports its claim of reducing carbon deposits and material degradation inside the combustion chamber by releasing this image. It shows two pistons after 50 hours of normal use. The left piston was used with the E3 spark plug. The right piston was used with a standard spark plug.

E3 plugs utilize a diamond-shaped electrode with a revolutionary edge-to-edge design. This patented design delivers a forced edge-to-edge spark discharge that projects the spark into the air/fuel mixture for better combustion. This design also creates a chimney effect that pulls the flame front out into the mixture-not around, like a standard J-wire plug. E3 says the result is more power, improved fuel economy, and carbon is practically eliminated.