Hi everyone.

My 2.1td (PR 5505, so mechanical injection)) is now doing valve-knocking-type noises.
It all started a few months ago, when it suddenly started making the noise when it had been running for half an hour. I turned it off, and it didn't appear until a few days later. It slowly began to appear more often, usually when I started it, but would dissapear after a few miles or if I started it again.
Now it always does it when I start it, but sometimes (only sometimes) dissapears after a while, and then comes back without me doing anything. So it doesn't seem to be a problem that's there only when it is cold.
Any idea what it may be?

It is also very smoky and with a very rough idle at startup, but this only lasts for the first ten seconds or so and only if it is cold weather.

Sometimes it also judders a little at just under 2000rpm; it just doesn't respond as fast as you'd expect it to.

Hope you understand something of what I'm saying, and you say if you have any idea of what the problem may be.

Regards.
Mike, from Spain.

Hi Mike, sounds like you need to look at the hydraulic valve lifters, perhaps replace the whole set to be safe as they've all done the same mileage.
I replaced mine a while ago with a cheapo set from ebay and had to do it all over again a few months later using a genuine set from citroen so sometimes it pays to just bite the bullet and splash out on genuine replacements.

Good luck, Colin.P

Hi Mike, firstly welcome to the madhouse! You've come to the right place for loads of friendly support and good advice on everything XM and much Citroen in general.
We have a couple of 2.1 Series I cars and find them a fabulous tool. What you describe could be several things from the symptoms you've described, but here are a couple of suggestions to start with.
The "valve knocking noise" could well be one or more of the hydraulic tappets playing up. I have one tappet that does this, but just live with it as it seems to have little effect other than being an annoyance, it could be an exhaust one which has a good working "pair" (2 valves per cylinder). Several breaking down however, would slow things down considerably. Much has been written here on these little blighters, they are costly from Dealers, and your mileage seems a bit on the low side for them to be troublesome unless they have/are running in dirty oil. Try the old "stethoscope" trick with a long screwdriver placed on top of the head and against your ear to source the noise.
As your car is earlier than either of mine, does it have a Roto injector pump? I ask because l only have experience of the later Bosch system which is regarded as far better. The smoke issue you describe could well be related to one or more heater plugs being "duff" coupled with a reluctance to initially fire on all cyliders, at such a relatively low mileage it seems unlikely that pump or injectors would be worn enough to cause this. Does the car fire/start readily from cold or need some cranking? Are you running on veggie oil at all? as I do down there, which is fine until the temperature drops, Roto pumps don't like it either.
The stumble at 2000 revs? -only a long shot, but have a look to see if the little cast ally fuel heater on the end of the block still has fuel lines attached. If it hasn't already been by-passed, do so. They go porous and are a notorious source of air in the fuel system. Fuel filter could be worth a check/change and check for air ingress too. If your car is automatic like ours, the "stumble " could be kickdown related.
No doubt others on here will have much to add and may shoot me down in flames (oops, sore point!! see my recent post in readers rides) Apologies if some of this may be telling granny how to suck eggs. At least you may have somewhere to start and any more you can add may help. It's difficult without the car in front of you.
Incidentally, where in Spain are you? we pass through regularly en route to Portugal. Also how does a leather interior fare out there?

Good luck and keep in touch with your endeavours Rodders.

Thanks for the answers.

Now that you mention it I think we'd changed the oil not long before it started making the noise... but I've no idea which one we put in there. Which one is it supposed to have?

Now the answers to what you were asking:
The injection pump is a mechanical Bosch.
The car is a manual one (I'll have to do the clutch at some stage, it's extremely hard compared to the BX's).
It always starts first time, even if it is cold. The only problem is that it smokes a lot. And no, it doesn't run on veggie oil (I don't know of anybody around here that does it).

We live near Barcelona; don't imagine you come this way to Portugal, do you?
And well, it's only had the leather since April, and it was (and still is) in good shape. It was taken from a 1990 V6 that was scrapped, and I've no idea if it had been garaged or not so...I can't really say if it stands spanish weather nicely.

And I must say for me at least it's good to know the most basic things; I'd read them somewhere but completely forgotten by now.

Cheers.
Mike.

Hi Mike,

Was in Barcelona last year, absolutely love the place.

You mention a "valve knocking noise", rather than a mechanical noise could this possibly be detonation or diesel knock as I know it?

This can be brought on by worn injectors and/or poor spray pattern. Do you know the history at all? (car not Barcelona!)

Hi demag!

I mention "valve knocking noise" because I know that it is a common thing, but I have not the slightest idea if it is such thing or something else.

And I do not know much about it's history, as it was first registered in Germany, and then brought to Spain (so all the papers dissapeared). Somebody bought it here and in a couple of years left it falling to bits, so it stayed for some time in a Citroën garage. The boss then bought it to fix it for himself, because the owner didn't want to bother about it. He said he intended to keep it forever (always as a weekend car, which is how he managed to do about 10.000miles in 8 years), but now that he's 70, and his wife can't walk, they couldn't get into it (sow low when parked...), so he sold it to me. You could clearly see lots of bits had been changed (but the garage paid them all, so he didn't have any bills or anything ), including the front suspension (of course it had gone flying to bash the bonnet!!) But well, it has never let me down (please don't you dare!), so it must be OK.

Hi Mike

I would agree with the others that the hydraulic tappets are the most likey cause of your noise. If that is the problem, it usually starts after an oil change and will quieten after a while, it can also usually be stopped by revving the engine, only to come back again after a few seconds at tickover.

Your smoking on start up could be a defective glow plug or two, or it may be valve stem seal wear, if it goes off, I wouldn't worry about it.

Colin. Thanks for that, I bought a set of those!

Peter.N.

May I ask questions about hydraulic valve gear noises?. today I have just finished replacing the radiators on my wifes 2.5. During the extensive bleeding process, with plastic bottle jammed in the header tank, I spent time with my head under the bonnet listening to the engine over a longer period of time than normal. One noise that worried me seemed to be coming from the cam cover, it was a irregular clicking noise, sort of click click ----click -----click click, the noise does not effect the running of the engine. I could almost say it was not a mechanical noise, more a combustion noise, but again it could be rocker sliding along a rocker shaft. Sorry I don't know the internals of the 2.5 turbo diesel, do they have rocker shafts?
Anyway gents has anybody heard this noise, and more important should I be worried. Please bare in mind its the wifes car I have to fix it and its my fault!

If the valve gear is the same as the 2.1, which I believe it is, yes, it does have rockers but it doesn't use them in the same way as an OHV engine. The camshaft operates about midway along the rocker with the valve on one end and the hydraulic tappet on the other. If the noise you describe is occuring at half engine speed the chances are that is it due to the partial failure of one of the tappets.

If it was a combustion noise it would vary according to engine speed. Combustion noise at tickover can be caused by leaking injector nozzle but it will normally either dissapear or get louder with an increase in throttle opening depending on the actual fault.

Peter.N.

Smoke on startup on Bosch mechanical units is curable in a tempery way.

Firstly of course is to BE SURE all 4 heater plugs ARE in working order... if they are and the car starts on ALL four then delvs into the smoky running then adjusting the pump timing can help cure the smoke!

Ive had this on a BX with Bosch, a Xantia with Bosch, and also an XM...

First step is to check the plugs, then if you are certain they are fine, on to ADVANCING the pump timing a little....

Rgds
Paul