When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It was probably around 6 years but only 8k miles that those plugs were in my car before I purchased it. When I changed them because of misfiring, the iridium electrode had worn down to a tip and were all gapped at 0.06 from wearing down. I'm certain you have more experience modding then I do but that's my personal experience with them.
Regardless of miles, 6 years seems like a long time to not change plugs.
I've never heard of or seen an electrode simply widen. Iridium is extremely hard which is why it's used, it gets used in plugs for cars who's change interval is 100k miles as a result. At that interval the threads seem to come out with the plugs... the material is very brittle though so gapping plugs that use it requires care. The spark jumps best from a sharp edge which is why the electrode is so thin on Iridium plugs. This exposes more of the tip too so it's not shrouded and has better chance of igniting the mixture cleanly.
I've fouled Iridium plugs to the point the motor barely ran (2jz) and once the fueling issue was cleared drove them clean pretty quickly. Pulling them later I couldn't tell they had ever been fouled and continued running them for many miles after. Copper conducts better for sure but the edges wear round more quickly and the gap will open faster. My last set of copper plugs lasted a good while, so far my current set has done well at higher power but they've not been in long. If they last I'll keep using them but as big a hassle as changing plugs can be I'll try Iridium if they have to come out soon to see if they work as well or me in this car.
I know. They are 2 inch spacers. They are 997 knock offs. The one cracked and I had it welded then it cracked again in the same spot . This time the crack went too far and I was told it could not be fixed. It is back to turbo twist wheels.
Update. It ran ok with the new coils and plugs. Just ok. It started misfiring on cylinder 3. Over the weekend I changed the plugs. This time I gapped the denso tt iridem at .022 inches. It ran much better. Still a little misfire on cylinder 3. I swapped out the coil with an good old one. Now it runs like it is supposed to. Lots and lots of power. Fixed a broken shock mount at the same time.
Note to self. I am comfortable what fixed the misfire on cylinder 3 after the plugs were gaped at .022" was cleaning the coil connections with contact cleaner.
