Another problem and its solving ,if You have a smoking BMW with N62 engine,mostly its due to bad valve stem seals. The valve stem seal problem is that the old valve stem seal becomes hard over time and doesn’t provide the proper seal between the seal and stem. This allows oil to pass through and enter the combustion chamber and exhaust. In addition, the old style seal does not seal on the inside to the guide, like the newer updated style seal. This creates an oil pocket underneath the seal that oil can accumulate in and make the problem worse. The oil consumption here is bad for a lot of different reasons. Obviously smoking, but also decreased cat life and blockage of secondary air ports. So we got this BMW with exactly same problem . New valve stem seals fitted ,new rocker cover gasket sets , VVTI motor gaskets and spark plug new tubes ,these common to oil leak on to spark plugs and causing engine misfiring ,so heres some pictures of this job .
By the way, some garages do offer head remove for this job or half head strip ,as camshaft and VVTI system removal is needed to get this job done ,but thanks to special tools we do offer this service without remove of any of these parts .
Thanks for reading and enjoy the pictures !

rocker covers removed ,all removed parts and bolts stored for operation
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seal replacement tools ,cylinder leakage test tool to hold the pressure in cylinders to keep valves in their place when spring is removed ,and new stem seals
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First fitted in , and heres the difference between new and old seal ,the center hole is stretched and rubber of its time and heat is hard and not flexible anymore
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