I had a similar problem. Oil leaking from the valve cover joint on to the exhaust heat shield plate and on to the exhaust manifold. Potentially a fire hazard. The fumes become engrained in the air cond filter and persist for some time. It's not an easy problem to notice due to the lack of space in the XK8 engine bay. You may have to remove the inlet air tube or the radiator head tank to identify the leak.

G.B. Australia

 

Oil smell at the motor. Passanger side air intake has some oil moisture starting from where the air tube comes from the front.…. . Some tzac tzac tzac noise depending on the throttle.… bit more…. And sometimes nothing. Rockers? Valves? Gaskets? Maybe cracked intake? And….i opened the oil filling plug that's on the same side…with the engine running. Almost zero smoke… no blow by gases….. The plug not rocking…. So no back pressure.……but some noise like whoap whoa whoa.….. So…. Valves not sitting right? Rockers? . I changed the sparkplugs relay and in pin 5 an numbered on the jack…. The pin had different colour slightly. All the rest were silver, 5 was a bit red ish…. Slightly. Advice?
On starting…. A bit of a rocky start and a bit of a rocky stop. Car pulls nice…. No engine lights.…. No smoke.
Some rockers…. Gaskets…. Cleaning? Maybe intake….. And maybe aparkplugs? Opinions from who had similar problems?

 

I must be lucky then. I pull the dip-stick tube out as a matter of course on the several occasions I have taken the covers off, and never had a problem replacing it.

 

How?

 

Oil smell - Mine was from right bank valve cover leak onto the heat shield over right exhaust manifold. Oil would accumulate and fall from the rear outboard corner in the rear outboard corner of the shield. That was fixed by replacing the valve cover and gasket. (Note: The non-metal valve cover can warp and not apply even pressure all around the gasket.)
Coolant smell - I had a stink in my passenger compartment from coolant leaking from the connections at the thermostat housing.

 

Have a good look around VVT seals. Mine had very small leak which smelled inside.

 

but what about the tzac tzac noises? And another question….. what do you think about fai oil pump ? Think it’s a British firm. Are they ok for oil pump?