Citroen XM Forum

Dieselman wrote: Thu Jul 08, 2021 6:23 am Your engine has two woodrfuff keyways'.
Was there only one fitted, if so, is that how it came to you, or was one missed?

Nope, --my-- engine has TWO keys just the outer one was badly damaged. I have used the woodfruff key from (single key type) spare engines crank which fitted tightly and is slightly longer top extensions. The outer key was very badly damaged by the pulley spinning. (The photo shows the empty keyway and was taken after I extracted the damaged woodruff key)

I suspect this specific weakness (single central bolt/small short key into the pulley) is the reason they changed to twin keys when the extra loading of air-con, higher amperage alternators and new pumps were added.

As for the misfire, that remains to be seen, I will run the car up to temp/investigate with the Aux-belt removed. I can use the damaged damper to prevent the belt coming off the timing cog as there will be no loading on it.

Moving on.....

It is RUNNING again.....with the Aux Belt --off-- and the 5 rib pulley attached to keep the belt running true and secure.
Ran it up till the fans came on, turned it off and walked away for the day.

<slight exhale>

I assume no misfiring.
I'm pretty sure the pulley bolt just wasn't tight enough and it shook loose.

This car hadn't had a problem with this previously, so its safe to assume it wont now.

If the pump locked solid, the belt would shred before the pulley comes loose.
Steel to steel clamped faces have a considerable coefficient of friction. With sufficient clamping force the woodruff key is unnecessary.

I did ZERO on the engine today as I am waiting to get the AUX-Belt/Pulley fitted.
So

Moving on......I decided to do some jobs that needed to be done before I buttoned up the cover/wheel arches, ECU box etc

ECU's all cleaned up ready to put back in their box. Inner wing in the engine bay/under the ECU box, I have painted on S50 Bilt & Hamber anti-corrosion-cavity wax into corners, seams etc. It is not "tidy looking" but visible areas can be cleaned up if the car become worthy of display, I will always leave seams and under box areas coated. Working in the wheel arch, brush coating wax into seams, loading where panels meet etc, this area is normally protected by the wheel arch liner so most of it will not receive a coating of B&H-UB (thick, black underbody sealant) Pre coating the front sub frame and right front chassis rail areas with S-50 wax before applying B&H-UB under seal. (Not a clue why the subframe was painted with red matt paint, this will be covered with black under seal anyway)

Your car is in very good condition.
The front wheel arch closing panel rust starts as a result of the bumper bracket being spot welded on, and no seam sealer applied.

Road dirt and water eventually take their toll.

This thread made me check the tightening torque for the crankshaft pulley bolt. Depending on the source of information the torque setting is different.

Haynes:
Stage 1 = 40nm
Stage 2 = angle tighten 60 degrees.

Peter Russek:
Stage 1 = 4.0 kgm
Stage 2 = angle tighten 60 degrees
Stage 3 = tighten to 17+3 kgm

Citroen Private car book:
Stage 1 = 7+/-0.7 m.daN
Stage 2 = angle tighten 60 degrees.

Haynes state there were no figures available at the time of writing the manual, so give these as suggested figures, though the last stage appears to be missing.
I suspect the Peter Russek and Citroen book figures will reach similar clamping force.

I don't see any reference to thread lock in the Haynes manual, but Peter Russek says to apply it.
Citroen state to clean the female thread out with a tap, renew the bolt and washer each time. I believe the new bolt has thread lock already applied. It is the old thread lock, which is cleaned out with the tap.

Standard engineering procedure for a rotating component would be to use thread lock compound, especially as this is a right hand thread, with load applied in the counter-clockwise direction.
A left hand thread would self tighten in such an application. Some engines now dispense with the woodruff key and rely soley on the left hand thread.

Cheers for those numbers, I would think I will be flipping the car on its roof getting it up to that point

I will be using Loctite-638 on the cog/shaft/pulley interface as well as standard Loctite on the threads......Double Bubble !


https://www.henkel-adhesives.com/uk/en/ ... e_638.html

Moving on.......

Right side wheel arch and wing etc all protected with Bilt & Hamber S-50 Front bumper mounting frame/crash protector beam and fan frame cleaned of the matte red primer and repainted, internals coated with S-50 using a pressure pot/gun and fine spray lance. I NOW STINK !!!!!!!!!!!!!!!

Aux belt not on yet but everything else attached/clamped and screwed on (left the cam belt lower & front covers off for checking).....

Car running fine, no misfire.....BUT, "hunting" at idle.