Oil leak

[Glynnrg]

Seem to have oil weeping from this nut on the back of my 550f can anyone tell me what it does?

[hairygit]

It's your camchain tensioner.

[Glynnrg]

Thanks:)

[Glynnrg]

Not good then as it doesn't seem to tighten just spins round and round

[hairygit]

Try a replacement nut first before getting too panicky, seem to remember it's a normal M6 nut.

[Glynnrg]

It's not the nut spinning it's the whole bolt 

[hairygit]

Ah, that is not good news, head off job to replace it, and not a cheap part to buy either. One bonus is you can do it with the engine in the frame.

[Bryanj]

If that nut is spinning your cam chain tensioner is not working and bad wear results, usually caused by a previous numpty using a screwdriver in the slot to try and force the tensioner to work---its only there to position the tensioner on rebuild.

Sometimes the tensioner mechanism can be fixed as long as the teeth are not broken

[Glynnrg]

Thanks for the advice even tho you are bearers of bad news