Update :

After all the repairs (replacement of valve seals, cleanup of oil passages inside cylinder head, cleaning inside the combustion chamber) and putting the new lifters in, there is still the same ticking. There are no related errors and engine seems to work nicely.

So, what are the chances of the ticking caused by a leaking exhaust manifold? I have been reading the ticking is very similar to lifter tick in too many cases and when I looked in there with the camera, I saw some carbonized spots around where the manifold connects to engine. After listening using a stethoscope the ticking is very loud there but it's hard to tell because the noise seems to travel everywhere on metal..

How can I test to see if there is a leak there?

Thanks,

Ozzie

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X5 4.4 01