Buggrit - anyone have some spare 2.0 exhaust valves?

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andmcit
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Buggrit - anyone have some spare 2.0 exhaust valves?

Post by andmcit » Sat Jun 13, 2009 9:10 pm

KYAC, the 2.0i TurboCT was on full song a few weeks back zapping cross country across South Wales
and though it may have been all in my mind seemed to be down on power over the last few miles
home although it was late, cold and I thought nothing of it until I investigated the following morning.
On starting there was an unmistakable additional sound of impending mechanical calamity so I
switched off and decided as there are a whole raft of additional issues to resolve I'd get back to it
when i was ready and use the Xantia V6 in the meantime. 8-)

Image

Well, today I decided to spare some time investigating in the sunshine and systematically removed
the belts off the engine in a process of elimination to determine just what the hell the angry loose
pulley sound on the engine. I did eventually find the cause of the problem:

Image

the damned tensioner outer bearing race decided to part company with its inner and leave the
timing belt clinging on by it's fingernails:

Image

It seems the timing has gone AWOL sufficiently to allow a delay of the belt to 'slap' the valves with
the pistons yet until I discovered the true enormity of the failure the engine has consistently started
immediately and apart from the slap otherwise sounds spot on with the timing with no pops/bangs
etc through the exhaust. The timing belt currently appears to be just in place by willpower and the
lower timing cover holding it!!

Is it possible the slackening of the timing belt has allowed the belt to either jump a few teeth but
not bend the exhaust valves!? I know a snapped belt on a 2.0i will bend all 4 exhaust valves from a
similar failure a few years ago on another Xm. I don't make a habit of running the cars to the limit
on their belts and am annoyed that a precautionary recent timing belt on this car (it's showing 30k
miles!! :shock: ) by an Indy specialist barely a few 1000k miles ago for the previous owner didn't catch a
duff or deteriorating tensioner. I've had absolutely no inkling of the sound of a failing tensioner either!!

Image

I'm expecting to actually hand turn the engine to timing reference tomorrow and see just how out
of true it all is between top and bottom and go from there and have a full new kit and water pump
in stock to fix the obvious outward problem but fear the valves may be mullared and am not in the
right frame of mind for a cylinder head off job. Just as well it's just had an MOT and been taxed as
otherwise it may have been swapped for another car I have in stock...

that said, does anyone have a spare head off a 2.0i (don't think turbo specific matters) or has a spare
set of valves they don't mind selling to keep this particular Xm going long term?

bollocks

Andrew
Last edited by andmcit on Sat Jun 13, 2009 11:06 pm, edited 2 times in total.

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Dean
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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by Dean » Sat Jun 13, 2009 9:25 pm

Hello Andrew

What have you done to that poor turbo you vandal :D
Should the worst happen i have a spare head and or valves for you, On the I.O.W :roll: but they would be available, i would think the valves are ok though, dispite half hanging over the cutouts in the piston crown they can take a little knock without too much damage, if the belt had let go altogether it would almost certainly of been bad news, but we wont dwell on that ;)

D
92 Citroen XM Prestige 3.0i Auto R.P5678
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andmcit
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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by andmcit » Sat Jun 13, 2009 10:08 pm

Cheers Dean.

I may need to take you up on the kind offer of the valves - please pm me an idea of £££'s!!

The last time I rebulit the remains from a similar catastrophe the inlet valves were fine but
all the exhaust ones had a neat 15 degree angle off true to what they should've been!! :(
I'll take the rocker cover off and study the valves when I turn the remains of the engine over to
get it to pegging positions for the timing etc on the cam/crank so will have a clearer idea if the
weather holds tomorrow.

Funny, you do tend to see cars on ebay with the belt snapping on start up rather than in full song.

Andrew
Last edited by andmcit on Sat Jun 13, 2009 10:25 pm, edited 1 time in total.

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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by Dean » Sat Jun 13, 2009 10:22 pm

The weather should be good tomorrow, well i hope so because im planning on some hydraulics fun :twisted:
If you dive in and find out what you need and let me know tomorrow i should be able to get the bits off to you this week, price wise i wont be looking for much, just cover the postage and a pint or two of LHM but we shall talk when things are known, fingers x'd for you Andrew!!

D
92 Citroen XM Prestige 3.0i Auto R.P5678
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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by andmcit » Sat Jun 13, 2009 10:32 pm

We'll see what falls out tomorrow. :? As I said, bollocks!!

I'll say one thing about the turbo engine bay. There's naff all space to even get the timing cover off
whereas you can get a bit spoiled with room after working on 2.0i normally aspirated engines!
Taking the top cover off took me ages to get the lower damned bolt out and my hands aren't the
size of tennis rackets either!! :x At least you'd expect hassles with a full v6 or 2.5TD engine bay
but a damned 2.0i?

Andrew

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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by Dean » Sat Jun 13, 2009 10:42 pm

I duno Andrew the n/a is pretty tight there too, i have to take the bottom pulley of to get the engines out! everywhere else is easy though, although having a/c and auto takes up more valuable space, now an early carb'd manual with no frills has an empty bay, and is all the better for it i say8-) (well maybe not the carb :evil: ) .

D
92 Citroen XM Prestige 3.0i Auto R.P5678
14 Mitsubishi L200 Trojan
89 Talbot Express 2.0 coach built Auto-trail Chinook

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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by andmcit » Sun Jun 14, 2009 8:08 pm

I can get the top timing cover off a n/a 2.0i without having to remove half the engine bay
whereas the turbo today has been a real PITA. The top engine mount had to get removed
to gain a remote chance of some already bleeding knuckle space. :x

The remnants of the timing belt were gingerly turned to a point where I could pin the bottom
pulley at it's reference point for the timing mark and at that point I found the top cam shaft
needed turning back a few degrees by approx. 1 or 2 teeth to align the cam reference point.

To gain a chance to gauge whether the valves have bent I decide to try getting the engine in a
temporary timed state using a tidy but used belt tensioner pulley before I get the new kit all
messed about. I fished off the stub of the old belt tensioner which remarkably was still guiding
the timing belt around it and slowly scraping light fluffy rubber deposits about the place! :shock:
The belt is toast for a whole load of reasons along it's length albeit the actual teeth on the inside
face are perfect and show no wear or splits when turned back on themselves suggesting the belt
IS recent and in fact a reason the whole lot may still be in working order (not sure about the 'good'
bit yet mind!).

The alternate tensioner pulley combined with the old belt now sit in their correct orientation
and I have just turned the engine over by hand about two full cycles of engine revolution back
to the crank pegging position whilst I had the rocker cover removed and had a long slow look at
the state of the followers acting upon the ends of the valves obviously paying a lot of attention
to the exhaust valves. The good news appears to be that EVERY follower disc is rising the same
height up towards the cam whether it's an inlet or exhaust.

Have I been fortunate and have a full set of working valves then rather than requiring a full off
head gasket and head rebuild job? Actually, I'm not sure of the next step. Do I chance the now
iffy timing belt and run the engine to hear it run for 30 seconds or continue now and fit a new
timing belt/tensioner and water pump working on the basis that internally everything is now
happy again in the bores!? :?: :shock:

One of the weirdest failures I've ever had was a CX 2.0 that literally had the valve stem snap
about a inch from the cylinder faced end which then got pushed upwards by the obliging piston
and punched a hole clear into the head jamming the engine and allowing water to escape into
the mess as the waterway was opened up. That happened on turning over the engine on start up!

Andrew

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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by Dean » Sun Jun 14, 2009 8:38 pm

Hi Andrew

It all looks rather promising imo with only being two teeth out i would say you have nothing to worry about, throw the new belt on and fire it up, i wouldnt risk using the old belt again, chances are it will be fine but i just wouldnt risk it.

close call though :shock:

D
92 Citroen XM Prestige 3.0i Auto R.P5678
14 Mitsubishi L200 Trojan
89 Talbot Express 2.0 coach built Auto-trail Chinook

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andmcit
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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by andmcit » Sun Jun 14, 2009 9:13 pm

Seems I may have dodged a bullet although there obviously has been some kind of contact as the
angry mechanical noise was from the top of the engine so presumably the valves were catching
the piston - of course at one point I thought it was the hydraulic pump making a racket as it was
about to let go...

It was an awkward situation as by the time I had started the car and popped out to investigate,
the noise was bad enough to want me to dive in to the car to switch it off quick smartish. It was
only after enlisting my father's help to have a listen having already removed the aux belts that
further diagnosis of the main timing belt was deemed necessary/urgent.

The ME5T IIRC (or whatever it's called) gearbox doesn't have the same cut out for the top of the
starter ring in the same way the BE3 gearbox does and I usually peg the teeth here to lock the
engine from turning to undo the crank bolt. Is there a knack to doing this on this alternate ME5T
gearbox?

Andrew

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Re: Buggrit - anyone have some spare 2.0 exhaust valves?

Post by andmcit » Sun Jun 14, 2009 9:19 pm

One more thing to worry about - what he hell is in the bearing of the belt tensioner as it's
all gone AWOL above the wterpump/crank pulley inside the lower timing belt cover - why didn't
Citroen design the lower cover to have a cut out to facilitate it's removal without the lower
crank pulley being removed; I found someone had made this "adjustment" to the design on
the last Xantia I changed a belt on after I'd struggled for ages to remove the damned thing... :evil:

Andrew

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