Volcane in Intensive Care Awaiting Extensive Surgery.

Chlorate · Unread post by **Chlorate** » 14 Nov 2010, 14:45

I started a thread earlier this week asking about XUD water pumps.

The pump in my car was leaking, so I figured it was about time to change it.

As it turns out; the pump in my car didn't like this idea, and took out it's frustration on the timing belt.

Luckily it decided to go when I was literally outside my house in Brighton after coming back from somewhere as opposed to on a motorway.

So another trip back to Kent on the back of a lorrey, getting my money's worth out of them. The AA guy was a Citroen enthusiast, so we had a good natter

I was preying that I was incredibly lucky and got away without the catastrophic damage that usually follows timing belt failure in these engines.

But alas, when I took the valve cover off this morning I was greeted with:

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So valve damage, piston damage, possibly cylinder head damage. Got to take the head off to find out the full extent.

Luckily I have an old head sitting around, could pinch the valves out of that at least.
No chance I could use the old camshaft too?

Good few weekends of work to breathe life back into it.
I was going to change the timing belt and water pump next Wednesday!

Ah well.

Wish me luck!

-Alex

Unread post by **CitroJim** » 14 Nov 2010, 16:57

Oh dear Alex

Did the pump seize or did its bearing collapse?

Another good reason for changing them as a matter of course along with a timing belt...

spider · Unread post by **spider** » 14 Nov 2010, 17:02

Not good

Cam in two or three pieces, as there is nowhere for the 'force' to go when the pistons ascend with the valves open, pushing them up (sometimes bending slightly) and snapping your camshaft.

You cannot really put a cam into that head, it will likely seize after a short time due to the bearings.

A replacement head is the sensible action here.

On a more positive note, the bottom end usually is not damaged, except in some rare(ish) cases.

Unread post by **citroenxm** » 14 Nov 2010, 17:09

WO WOW HOLD ON!!!

Spider: Firstly, Cam will only sieze IF the replacment CAPS are too tight! Ive done this 3 times now, with GREAT success!!!

Check your valves first!!!!! I have broken a cam and found NO bent valves!!!!

Use a screw driver to lever the tappet down under the cam!! If it moves freely its NOT bent! Trust me! Ive done this TWICE now, and only JUST last week done the same on a 405 that broke its belt!!

If the valves all move freely thenleave the head on... Get a Cam shaft, ALL the same on later XUD engines, even xantia ones without a Vac pump, the only thing you will need to do it possibly match the cap bearings...

However, you can get away with that sometimes, Ive a good collection of caps from old heads... I got away with a Cam and centre cap..

Then with the pistons halfway down the boares, use the 16mm nut on the end of the cam, belt end, to check how tight the caps are...Use your own experiance to determind how tight or slack the Caps are...

Then check valves clearences...

Piston damage is rare, due to the DEAD FLAT valve over pistion design.. valve bend is also rare, and its useually the cam and caps that go...

Id seriously check them asa above, if you dont need to take the head off, I wouldn't

Paul

Chlorate · Unread post by **Chlorate** » 14 Nov 2010, 17:12

Not sure exactly how the pump failed, was going to take it off to have a look, got as far as getting the crank pulley off and rain stopped play.

Ah i was worried that would be the case with the camshaft, bugger. The head was only a year old

-Alex

Unread post by **citroenxm** » 14 Nov 2010, 17:13

Chlorate

SEE ABOVE!

All is not lost if NO valves are bent

Paul

Chlorate · Unread post by **Chlorate** » 14 Nov 2010, 17:16

That's good news Paul, will give that a go next weekend. Have taken the head off that engine before and it's really not fun.

How likely is it that the head itself got damaged?

-Alex

Unread post by **citroenxm** » 14 Nov 2010, 17:18

If ALL valves are Clear and free and straight, there will be no head damge!

The engergy from the piston hitting the valves goes stright through to the Cam, which takes the brunt instead!

What speed, or how fast was the engine going when the pump Siezed??

Paul

Chlorate · Unread post by **Chlorate** » 14 Nov 2010, 17:21

Barely ticking over, was just coasting into a junction when it happened. Probably the best case for getting away with it methinks.

-Alex

Unread post by **citroenxm** » 14 Nov 2010, 17:29

Yes, if idleing then I DOUBT VERY much any valve will be done!

Also only one break, have any caps broke??

Another sign of a light hit... Looks like a Head Stay On Job..

Paul

Chlorate · Unread post by **Chlorate** » 14 Nov 2010, 17:43

The middle bearing cap broke, the other two were ok. Feeling rather optimistic now, can't do anything until next saturday. Will post updates, see how it goes.

-Alex

Unread post by **citroenxm** » 14 Nov 2010, 17:45

Ok,

With middle cap brke it will have bent the Cap mounting studs too a tiny bit, so you'll need two of those...

Shout if you need studs, theres a few here..

Paul

Chlorate · Unread post by **Chlorate** » 14 Nov 2010, 17:53

Will do Paul, I may be able to recycle the studs in my mucky old head.
Thanks for all the advice, hopefully it won't take quite as long to mend as i thought

-Alex

spider · Unread post by **spider** » 14 Nov 2010, 19:16

Sorry

... I was always under the impression it was not practical to start having a cap swap, due to the fact you would be there forever with plastigauge to get the clearances spot on (and an endless supply of caps)

As you were

Unread post by **CitroJim** » 14 Nov 2010, 19:39

Strictly speaking, the cam caps shouldn't be swapped. The cam journals are line-bored at manufacture and thus every one will be a bit different...

However, as Paul says, you can get away with it if you have a selection of caps and furthermore, I'd most certainly second your Plastigauge recommendation Andy, to check that there is clearance on the new cam cap. If the cap is too tight then damage will result...

If a cap is a bit tight on test then I see no harm in easing it a bit with a scraper as they did in the old days with white-metalled big ends. My dad has told me many of his adventures of scraping in new big ends on various old vehicles he had when he was young. Not sure what the clearance should be but around 5 'thou should be OK.

Fact is, replacement XUD heads are not common so anything that can be done to save one is good. The only problem is that new cam caps are unavailable as spare parts so it's a case of rescuing them from scrap heads.

As you both say the chances of valve and/or bottom end damage is unlikely...