I agree, I think the keyway in the crankshaft is rounded out.I don't know what you do about it.
Incidentally I don't think it has slipped because of a loose pulley bolt- I think it's the opposite- it's loose because the key has failed. I believe that keyed crankshafts don't have to have an insanely tight bolt anyway.
But don't rely on my opinion- my experience is limited to changing 2 timing belts, one keyed, one not.

 

Not absolutely sure on Renault but on many engines the key is only to line up the pulley
and the bolt is what holds it whatever you decide use a new bolt.

 

Thanks guys

Yeah will be using a new bolt and red locktite

See I'm lead to believe some k9ks don't know if earlier or later have no key and are held by the bolt
And locating pins

But some have the key which locates like mine

I'm not sure how to work it as I'm not taking any chances!

If needed I will line up the timing mark and weld the gear and the crankshaft part at the locating pin to fill the gap

But I'm hoping someone may have a better option than me welding it because I wouldn't want this to happen again

 

Should I weld the Woodruff key to the crank or would I be better off cutting a extra slot and adding another woodruff key?

 

Yes, maybe, don't know.
It is certain that the visible bit of crank slot is worn but until stripped down, will not know for sure.... it may be purely local and a new key will sort.
I'm not sure I would weld the new key in.
With decent facilities I would weld the slot and re-machine.... like getting the crank out and onto a milling machine.
Could weld and clean up with a dremel in situ but that would be a right ball ache.
Also consider if welding in situ that the welder earth should be on the crank.... on the block means the current has to track though the big end bearings and that can lead to welding them up.
Metal epoxy may be the answer but again, depends on actual state of the slot in the crank.
Old fashioned engineering would be to drill and tap a hole into the join between pulley and crank and stuff in a grubscrew.

If I recall correctly, keys on this engine are not so much to guarantee location but to shear if a jam so that the bottom end of the engine is protected.

 

Plan on porting the head if removing don't know if anyone has done that on these engines?

Had a good Improvement on other engines it really depends on the Quallity of the casting if it's not great a port makes a decent difference also if the holes can be enlarged to much of a different size

Some are already pretty decent so not worth touching

 

Was thinking about either cutting another slot opposite the stock one to add a second woodruff key?


Or I was thinking about braising ?