Quote Originally Posted by Julian B View Post
When I had a previous misfire fault which turned out to be skipped time on one cam I bought a set of OEM plugs from Land Rover. They were motorcraft units. I installed these and the car was never driven subsequently, just a cheap experiment for me towards confirming a dead engine.
I kept the plugs, even in the original boxes.
I used these to replace the ones in the current engine that was misfiring, and it seems this was a bad move.
This car had a low km engine replacement sourced here on the forum from a regular contributor. Part of the exchange was new plugs and leads and the plugs were OEM also, but lasted less than 10,000km.
Not planning on using these plugs in the longer term. This is a great lesson on plug technology for me and that using OEM is not necessarily better.

I hope this explains the issue, but yes I think hellishly unlucky to get repeat misfire on that cylinder.
Ha ha that's terrible luck. But then again if it wasn't for bad luck sometimes we wouldn't have any at all.