Originally Posted by
Larry Hitze
Dave, the biggest problem that you might have is when or if you do decide to replace them they won't come out at all, stuck. Other than that they will probable function just fine for years to come and I agree with your statement. I changed mine a couple of years ago at 50000 miles and a couple of them acted as if they were frozen in there for a while and were quite difficult to turn making loud popping noises.
That is a very good point, I expect that they are treated in an effort to stop them binding to the heads. I will remove them at some time to prevent this.