Man that's crazy, I hope to never have to do that again.
So I was talking to my buddy about the issue a minute ago and asked him if his misfire from the old plugs was gone ans he said it was, then he was talking about that if he had to he was just going to put the old plugs in and sell the car. I was like wait a minute, that sparkplug would have blown smooth out of the cylinder when you started it up.
Then he says that he had put the old one in and it seemed to hold. So I asked him what were the plugs old and new he said the old ones were NGK and the new ones were Denso. I am wondering if there is a difference in thread tolerance on the different plugs.
I handed over buying parts over to him a few months ago (drills, taps, endmills, inserts and other machinery consumables for the mill and lathe). Well he came up to me and started asking about the taps and what did the H-1, H-2, H-3 mean, so I explained that even though the thread pitch is the same the fit is tighter or looser depending on what grade the tap was and some were for more precise holes and maximum strength and some were looser for easier assembly and such.
Could it be that his new plugs are a little on the looser side and the old ones were a little tighter and this is what caused the threads to pull out?
When I got there that day I looked into the sparkplug hole as best I could, and though the threads seemed slightly rounded I could tell the threads were there. I inspected all his plugs looking for signs of aluminum in the threads, but every one looked good.
Jeff
Originally Posted by J57ltr
