I sometimes wonder why i try doing preventative maintenance!
So I did a full service on the Plus 4 (duratec engine) for the first time since a full dealer service, I took out the spark plugs to check the state of them and the gaps.
I was very careful refitting them - conscious of not cross threading etc. However, number 2 plug does not "nip up". It carries on turning with just under 10Nm of torque. I tried comparing the number of turns with the other plugs, did that to the number 2, then went perhaps 3/4 turn further with this steady, but slightly low torque. I dare not go further. I have looked down the hole and cannot see any swarf on the piston or sides of the hole. The plug seems ok. I cleaned the threads with a cloth on a stick - nothing untoward.
When I first got the car (from a far away dealer), it failed on my first journey and went to my local dealer who found the plugs swimming in water and corroded. So my theory is that the threads were slightly damaged when the number 2 plus was extracted then.
So what to do? I can leave it torqued up to the just under 10Nm and hope. After all it has been to Angouleme and back twice like that. I have a home made engine cover which should take the impact if it pops out. Or perhaps take it somewhere for a helicoil fitment. What's the wisdom of the forum on this?
Cheers
Nick
