I have a 2006 colorado, and yesterday I found out the spark plugs i bought were too long for the engine even though they were matched specifically to my vehicle and now I have to replace the entire engine at my expense. I have ran on these spark plugs for five months and never had one problem and now in one day they have trashed a new engine. I am running E3.66 plugs in my colorado 3.5, has anyone else had problems with these plugs?

 

The same thing happend to me... Im actually getting ready to send the plugs to the manufacture and try to get them to fix it. This is crazy ****!!

 

I guess you have to either fix or replace them...but do you mean to say that they were operative for 5 months?