Is this Normal or an issue

[UKChrisT]

Not sure if this is the cause, but sometimes my car will produce a loud knock when in movement or when switching the keys off, the noise comes from the engine area, it doesn't always happen.

There is also a smell of strong burning oil (as mentioned in a separate post), I have attached a picture below, could this be the reason? The image is of one the spark plugs at the bottom, you can't really see from the picture but at the bottom there is oil and it seems to bubble when the engine is running?


Thanks in advance,

Chris

[mcgee9t2]

I would say thats not normal.

Ide try replacing plug. if that dont fix then might have to get a helicoil or what ever there calledput in to keep the seal tight