i changed my spark plugs about 5 months ago and i took them out yesterday just to check them out. i found that the rear plugs look really dirty in the thread area. also a couple of the plugs look like they are burning more than the other plugs.

i cleaned the threads and put the plugs back in but i hav not driven the car yet. are these plugs bad or is it normal for this to happen?

and for the plugs that look as if they are burning more than the others, what could casue this? also, as a result of the plugs burning to much, can this afffect my engine oil? (burning oil, etc?)



thank you in advance for your help

 

Unfortunately you have no picture, and a picture would really have helped

 

i will try to get a pic today but i dont think it will happen cuz my sister leaves home b4 i get there and she always keeps her digicam. (i dont hav one)