Oil in Spark Plug Well
 

A few miles from home 2003 XK8 went in Restricted Performance Mode. CEL Light came on. Before I got home Restricted Performance went away but CEL Light stayed on. Checked for Code and found P0303. When I pulled the Coil on #3 Cylinder I found Oil on the Coil and there was quite a bit of Oil in the Spark Plug Well. There aren't any signs of any leaks on the Valve Cover. Can you change the Spark Plug Seals without removing the Valve Cover or do you have to remove Valve Cover and change all the Seals?

The well seals are large o-rings in the covers, so you will have to remove them. I don't think those seals are available separately so you have to buy a set. Change the cam cover gasket and the small seals for the fasteners at the same time to avoid future leaks.

NO - the cover must be removed as the seals sit in grooves on the underside.

https://cimg3.ibsrv.net/gimg/www.jag...75af8929c3.jpg

Spark plug boss seals are available from Jaguar separately (P/N AJ87206). Some members report having successfully re-used camshaft cover gaskets but I always prefer to replace the full set whenever the cover is disturbed.

Graham

Thanks for the replies. I ordered a complete set to change all the Gaskets and Seals.

Might be excessive blow by
 

Worth doing a quick check if there’s oil in the breather pipe as it could be excessive “blow by” forcing oil through the seals.

If breather pipe is clean, just carry on as you’re doing