Brown Ceramic Spark Plug

The burnt area looks much worse in person than you can tell from the pics.

Brown ceramic spark plug. The plugs were also very tight and took a lot of grunt to get them out. Every plug i pulled out seems to have burnt ceramic insulators. Sorry for the crappy cell phone pictures. Burned ceramic means that combustion gasses are leaking out right.

Why would this happen with only 60k on the plugs. Engine is in order. Ok changed the plugs in my wife s 4 7l today. Spark plug color oil fouled.

Caused by piston rings or cylinder walls that are badly worn. Lead fouling generally shows up as yellowish brown deposits on the spark plug s insulator nose. Too much oil is entering the combustion chamber. A normal spark plug will have brown or grayish tan deposits on the side electrode.

No deposits from fuel additives containing lead or from alloying constituents in the engine oil. You can clean the spark plugs or you can just wait for them to dry out. Welcome to sau community like most online communities you must register to view or post in our community but don t worry this is a simple free process that requires minimal information for you to signup. I couldn t focus on the plug.

Spark plug condition identification insulator nose grayish white or grayish yellow to brown. Here are the pics. Everything is just fine with your spark plug. This can be caused by a dirty air filter excessive driving at low speeds too rich.

Pretty sure your plug labels are incorrect. You can reinstall the spark plug. Lead fouling can cause your engine to misfire only at high rpm and under hard acceleration. A normal spark plug will have brown or grayish tan deposits on the side electrode.

Black dry soot on the electrodes and insulator tip indicates a carbon fouled plug. Spark plug insulator is brown welcome to sau community. This condition commonly occurs when gasoline contains too much lead. Oil may also be pulled into the chamber because of excessive clearance in the valve stem guides also if the pcv valve is plugged or inoperative it can cause a build up of crankcase pressure.

Anyway on all of my other plugs the insulators were completely white. However because spark plugs are changed frequently in racing. I inspected the spark plugs and applied some of that dielectric grease inside the tube not on the terminals before putting it back in. On this plug it looks burnt all the way around right above the metal case.

Be apart of sau community by signing in or creating an account. The dealer put the last ones in and they are denso. Mixture setting and ignition timing are correct no misfiring cold starting device functioning. Or an internal crack in the spark plug s ceramic insulator that shorts the plug to ground also can be the culprit.

The rich one is right but the lean and optimal should be swapped round a lean mixture increases the heat of combustion and tends to glaze the ceramic of the spark plug and burn off any deposits that may have accumulated leading to the very white clean insulator on the right of the picture.