The stocker NGK's dont seem to last 5-6K miles in my car before it starts idling like it has a mild cam and randomly starts throwing a p0300(random misfire) code . 3 sets of plugs have done the same thing in my car . I keep putting the stockers in because I get them free from friends who are chevy techs and Im still on the stock pulley so I dont need a colder plug . Change to new plugs , and its all good for awhile . The kicker is , the plugs I take out dont visibly appear to have a thing wrong with them . Im not the brightest when it comes to reading plugs , so I included a pic . If someone knows what their talking about ....please comment

1 NGK plug(on the left) ....the darker tan porcelin is from a friends SS ( stock with 5K miles ) , the other is mine after 6K miles . The porcelin is still about white( VERY light tan) and the back side to the right of the electrode post theres very slight black speckles on the porcelin . The top of the electrode post itself looks like a VERY thin coating of whitish metallic dust . The rest of the tab is sooty and the perimeter of the plug where it seats to the head is sooty as well . Is it a healthy looking plug , or nay .

 

that looks like my old plug your holding

 

My car idles very odd but so far I havent thrown any codes (after 12,000 miles). I havent checked my spark plugs probably should....

 

i think your supposed to put your tounge on it when the car is running

 

Are they wet when you take them out? You get gas from the same place all the time?

Possibly try a colder plug see if they last longer or not.


Kyle

 

No there not wet at all .

 

two things i would check. first i can't really tell from the pictures but are the plugs steamed clean? if that's the case they will be whitish on the tips around the actual spark. if that's the case your head gasket is shot. if that's not the case you may have bad rings.