Should the state of this plug worry me?

[Joe Smart]

So on Friday I did a quick Plug and Pack change on my 172, Apart from the obvious plug that was not firing on 2 (which is why I was changing them)
The condition of 3 and 4 around the bolt head and ceramic was odd compared to 3/4


I was on a tight time scale so could not get too involved in looking into it deeper so I'm just wondering if anyone else has had anything similar.
I've got my fingers crossed the HT Lead wasn't sealed properly or something and water was getting it :coldsweat:

 

[LeeRS]

Probably just havnt been changed for 10 years

 

[jamesycc]

wouldn't worry. The spark ends look ok for old plugs and they are slightly more important. Just a bit of corrosion on old plugs I suspect as water and oil get down there quite easily.

 

[Joe Smart]

wouldn't worry. The spark ends look ok for old plugs and they are slightly more important. Just a bit of corrosion on old plugs I suspect as water and oil get down there quite easily.

Yeah I was having a misfire on Cylinder 2 but was just curious as 1+2 looked fine, 3 was a bit iffy and 4 was that badly corroded. Thanks for both of your replies putting my mind at rest.

 

[jamesycc]

misfires in my experience on these cars are either the coil pack failing or an injector failing. These seem to be the most reoccurring causes. 4 is the closest one to the oil fill cap so they fill up with fluid more than the others.

 

[Joe Smart]

misfires in my experience on these cars are either the coil pack failing or an injector failing. These seem to be the most reoccurring causes. 4 is the closest one to the oil fill cap so they fill up with fluid more than the others.

The plugs and Pack fixed the misfire but on Idle it still seems to be 'Hunting' so I'm thinking possible air leak on that one but that is for another day 🔨

 

[Mat Jones]

You have not put the pipe at the back of the manifold back on possibly?

 

[Joe Smart]

You have not put the pipe at the back of the manifold back on possibly?

Could be but it was hunting before I changed them, At the time is was hunting with a bad misfire at town speeds, Plugs and Pack fixed the misfire but not the hunting. Perhaps the previous owner has left something off so I will have a look tomorrow.