Thats normal, the average owner may barely get an oil change done.
I bet that jewel ran reallll nice.
I have a whole engine that witnessed that kinda of abuse.Thats normal, the average owner may barely get an oil change done.
I picked up an XJ not too long ago that had the same condition plugs. Still ran fine, but got happier once I put in new ones.
I bought a '92 explorer years ago with 200k+ miles as a parts truck. Was told it had a cracked block but turned out to be blown out intake manifold gasket. While I had the manifold off, I changed plugs. It had 5 shiny new plugs, but #6 (the one really hard to get to at the firewall) was a factory original with no electrode left.