A couple of years ago, I changed the plugs in this thing, and the truck ran great for a few weeks. After that, it started to sputter and lurch, like it wasn't running on all six cylinders. Checking over each plug, I found one of them had cracked. When I went to buy a replacement plug, the mechanic said it was the sort of thing that could happen upon installation, if you cranked them down too tightly. While that may be possible, I didn't believe that was the case for me, for the plug hadn't cracked until several weeks after installation. I just figured it was one funky plug, and left it at that.
|That Sparkplug Sucks!|
I don't know why a spark plug would blow up like this inside an engine. I'm inclined to think there is something defective about these particular plugs, though they are ACDelco plugs, which are generally high quality. Regardless, it is clear that this particular sparkplug sucks!
There have been warning signs before a plug fails. The truck will start rough and begin to lose power going up hills. When I ask a mechanic about this problem, they generally tell me the thing needs valve seals. That may be the case, as this is an old engine, but I don't see how that would cause the sparkplugs to crack. It's a curious thing, indeed.