noisy XM valve gear

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sdabel
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noisy XM valve gear

Post by sdabel »

Earlier this year the crankshaft pulley on my 1995 S2 2.1 TD gave up and had to be replaced, finding the problem and getting the correct part means the car was off the road for several months. It is now running but there is a problem…..
It is blowing white smoke under acceleration and on low revs has a loud rattle (valve gear?). This reduces as the car warms up and at higher revs. I have given it a good hard run and put injector cleaner through the tank but no improvement. It also seems to have a bit less power at low revs but still fine on the highway.
Any suggestions on what this could be and how to check? From reading other posts I am thinking it could be the timing belt is out, or perhaps the injector pump timing (mechanical pump on mine)? I am also wondering about the cold start mechanism and perhaps gunk in the tappets? Somewhere I read about valves not seating properly if left open state for some time.
regards
sean (from sunny but cool adelaide)
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Post by RichardW »

Hmm, did the auxiliary belt wreck itself? It sounds like it might have come off, and some of it has disappeared inside the cambelt covers and the belt has skipped a tooth or two - you certainly have all the symptoms of the belt being out. I suggest you do NOT drive this car any further until you have ascertained the condition of the timing belt, and the status of the timing. Don't want to be a doom monger, but taking the head off a 2.1 to change a few bent valves is not likely to be much fun...
If the belt turns out to be OK, then you need to look perhaps at a sticking injector, or possibly water in the fuel.
Get the covers off and let us know how it looks.
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Post by Peter.N. »

You could have a hydraulic tappet or two sticking, they can make quite a clatter but usually go quiet after revving the engine, but check what Richard said first. If it is tappets, some flushing oil after the next oil change might help, if not you will need to remove the camshaft carrier to replace any defective ones, not an easy job but easier than taking the head off, I know, I've done both!
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Post by Peter.N. »

It has just occured to me, that the failed crankshaft pulley (presumably the rubber damper section fell apart) necessitated refitting the timing belt, if the problem has existed since then, it could be that the engine has not been timed up properly, as Richard suggests.
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Post by sdabel »

Thanks for the replies, yes it was the rubber damper section of the crankshaft pulley that fell apart (and took out some of the timing belt cover with it). And the timing belt had to be refitted- it had been replaced along with the water pmp and tensioner less than a year and 1000Km ago. Both of the auxillary belts were also replaced with the failed crankshaft pulley.
The mechanic who did the work has now replaced the timing belt twice on this car using Haynes both times- diesel Citroens are not common here. Is there an easy way to test if the engine is in fact timed correctly? The fact that it gets better when warm makes me think that it is not the timing belt. Although it is certainly blowing a lot of smoke.
He is thiming it might be the timing of the injector pump(s). Does this sound reasonable? I was going to take it to a diesel injector specialist to have this looked at next.
regards
sean
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Post by Peter.N. »

I have timed up several just using bolts to lock the cam / pump sprockets, but as the location hole to lock the flywheel is so difficult to get at, I usually just put a mark on the crankshaft sprocket. This has always worked satisfactorly until I did a friends 309, which when reassembled was very difficult to start, although no knocking, I found it was actually a tooth out, when I was tensioning the belt I must have moved the crankshaft, ask you mechanic if he locked the crankshaft. If the timing is out it will normally affect the performance, what does it go like?
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Post by sdabel »

He said he used a bolt to lock the cam in place. However it may have been out before and the loose crankshaft pulley hid this?
Performance is definatly down. So all sems to point to the timing, how can this be checked?
regards
sean
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Post by Peter.N. »

Only really by locking the engine with a rod into the flywheel locating hole behind the starter, not very easy to find unless you take the starter off. You can shape a piece of rod to reach, you need about 3" straight, ground to a point so that it will find the hole more easily, then bend at 45 degrees for about 10" then straight again. You can if you are lucky fiddle this into the hole. When you feel it enter the hole, you need to rotate the engine until you feel it drop into the flywheel, it will then lock the engine. Then check whether the bolt holes in the cam and pump sprockets are in line with the holes in the backplate, you should be able to insert bolts into both, 6mm I think. If they all fit OK if not the one that doesn't is out.
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Post by jeremy »

Its rare for more than one thing to go wrong at a time (yes I know, whenever you take something apart you find something else but usually you've known or suspected it, its consequential damage or on its last legs!) and I would have thought that you would have noticed problems other than the pulley - so chances are its timing and I'd start checking there by putting ALL the pins in - ie no shortcuts.
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Post by sdabel »

Hi Peter,
Many thanks for that. I will let him know and check this before taking off valve cover- that scares me!
Forgot to mention before, it is hard to start- always started first time before. Now takes some cranking- brand new battery.
regards
sean
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Post by jeremy »

Interesting to think of it this way - Suppose you'd just bought this car and knew nothing about it - we'd suggest air in the fuel, possibly glow plugs, injectors - and so on - then you'd do all this, tell us it was still as bad and we'd all be guessing and eventually you'd give up and come back 3 months later and say - someone'd found it was the cambelt!
Now if you told us the previous owner proudly told you he'd done the belt himself - what would we have said?
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Post by sdabel »

Ok, point taken. Will get the timing belt checked......I will post the results. Thanks to all for the advice.
regards
sean
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sdabel
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Post by sdabel »

Just got the car back today from a diesel specialist. Injector timing was out a fair bit and the timing belt was off. My theory is that when the pulley self destructed some bits got caught in the timing belt causing it to jump a tooth. How I didn't bend a valve I don't know!
Many thanks for the advice.
regards
sean
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