Well have not noticed any antifreeze levels dropping.. the other plugs were black and smelt like fuel...if she knew how to pressurize the hole i could see if it bubbled back through radiator..i cleaned plugs and had it running ok,,now assume they are foul again lost power and starts little hard...did notice gas smell other day..had not been there before and when pulled in to garage to park heard a bubbling sound...???? now can i do just this one cylinder or does that make any sense seeing as its apart and all...??any thing else i can do??? thank u