Citroen XM Forum

I can only think that valve guide really was holding the valve on rotation and it jammed down and was struck by the piston.

Stripping the crank key is unusual.
Just the one for the auxiliary pulley, or the timing pulley, as well?

AUX pulley key......I checked it last night, it is VERY short (from the factory) Looking at it the woodruff key is a single one used for both the crank cog and the aux-belt pulley.
I would say the woodruff key is just about 1/4 the length of the channel in the pulley (if that).

Is there a method of removing the crankshaft cog ?....so I can fit the parts from the spare engine....
Thinking I will have to do this

Which way did the key shear? (pully advanced or retarded compared to the shaft)

I have sacrificed a nice little modelling chisel on the remnants of the woodruff key but I have got the lower timing cog moving. I will recover a replacement woodruff key (and cog if required) from the spare engine.

I have pinned the epic pump & the crank, still have to pin the cam but need to remove the engine mount (but a visual check it looks like the holes line up).
One thing I noticed last night was that the suspension pump was VERY stiff to rotate....this morning it rotated quite free.

xantia_v6 wrote: Tue Jul 06, 2021 10:52 am Which way did the key shear? (pully advanced or retarded compared to the shaft)

The pulley sheared off the woodruff key and loosened itself, this then damaged the back of the pulley which is Fubar'd now

Oooo was there a hydraulic pump or system issue that caused a lock up...

Has the actual timing moved or has it all pinned. Up correctly?

as said, it "looks" like it has not jumped a tooth (but still need to pin the cam.

JimE has noted it might be a accumulator problem or a power steering problem locking the Hydra pump...........(IF that is what is happening)

When you restart the engine, do it with the regulator pressure relief bolt slackened off, to isolate those last two possibilities.

Wasn't the woodruff key design rethought, so each pulley has its own key? It's been a long thread...

Remember this is not the original engine so I do not know the provenance of the block/crank.....it only has one key that I can see but it is had to see fully until I have the cog wheel off.

The question is how to test the items that may be causing these obviously intermittent problems because I do not think I can take yet another bite on the bum.

Crank cog is coming off after I destroyed a modelling chisel knocking back the remains of the woodruff key and got a couple of screw drivers behind the rear lip.

There is a chunky thread on here ("Main crank pully loose") from 2009-11, all about the two pulleys, and the keyway/key changes.
Not sure whether any help.

Wonder whether some loctite fluid on the shaft might help stop movement?