Hi. Changed my sparkplugs last week. First three had normal wear, fourth had wet oil in the well and on the plug.

I've been to my local garage who are good and honest with the more basic stuff but I think a couple of the guys struggle to diagnose the more in depth stuff. They have suggested valve stem/ piston ring seals. Does this seem like the most likely reason?

2011 Octavia vrs, 112k on the clock.

Thanks

Surely if there's oil in the well whilst the plug is being extracted, that's where the oil on the plug came from? 

More likely valve cover seal leaking into the well?

 

 

If it's a wet carbon fouled plug then could be stem seals, turbo or scraper ring problem. But other 3 ok. As @Wino says the oil in the well external to the plug electrodes will be leaving valve cover. Pretty common. There's a big seal the whole way around it, big job to change it, monitor it. If it is not excessive leave it. You may also spot signs around the seal around the front and back of engine where the valve cover meets the head. Again, a little bit of oil build up is ok.  Don't change unless there is a significant problem.

 

On this photo with the intake removed you will see part of the seal exposed along side the green line I have drawn in.

 

 

Edited 21 July, 20214 yr by TheClient

Ok thanks for the advice