Earlier readers will have heard my query re the fluctuating coolant in the expansion bottle of my 1990 Citroen BX TGD. Well the head appears cracked and repair seems the order of the day! But the best way forward without buying a new engine???
The current head has been skimmed 3 times hence may not take any more. In the garage yard where I have taken the car is an F Reg 19RD with 200,000 on the clock which is being dismantled. The garage is sending my head for testing - not sure whether leak down or pressure but if it is not reusable this other head may be fitted after skimming and testing: (the garage assure me the engine on the F reg is newer than the car - incidentally its gasket has 2 notches only - does this mean it has never been skimmed?) Alternatively, another garage suggests boring out the chambers so the existing head can be reused - better the head you know than a second hand replacement they say. A further source tells me that 5 notch repair gaskets can now be used - 2 above the standard maximum. In all these options what is the best way forward? I don't want to buy a new head - @£425 - but which would be guaranteed as opposed to no guarantee on a second hand head. Further, - is it true that alloy heads over 10 years suffer from metal fatigue?
And no, I am not prepared to scrap the car - motor car masochism is fun!
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> The current head has been skimmed 3 times
? What have you been doing to the poor thing ?
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I would skim the head off the other engine and fit it with a 3 notch gasket. Make sure you have got a good quality antifreeze as well. I t may be worth fitting two washers to each head bolt. I have had 2 or three cases in the past where the bottom of the stud hole has got muck in it and the bolt bottoms before being fully tight. This would obviously cause the gasket to go!
Sorry to ramble.
Matt
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incidentaly , the thickness of the gasket ie no of notches is to compensate for the piston protruding above the block. not the thickness of the head
Matt
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If you must keep the car, surely you can find a second-hand XUD engine for this. Maybe a ZX or Xsara, or even a Pug 306 that's had a rear-end crash? You might even end up with a TurboD from a Xantia and put some ooomph in that BX. It will probably be reasonably cheap, too, in comparison with repeated head gasket replacements. Much as I love my BX (most underrated car of the last twenty years anyone?), it wouldn't get away with this kind of bad behaviour.
Chris
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Sorry,
The only answer is to get rid of the whole shebang. Forget loyalty, masochism or whatever you want to call it. Get rid, buy yourself a relacement. Plenty of BX, ZX, Xantia's to have a look at for next to nothing..............
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This reply will include some info correctly stated above but I want it to "stand alone" as a complete reply hence repetition in places.
Andrew,
In my experience the very best thing with an XUD diesel engine is never to let them overheat in the first place therefore avoiding the head being lifted in the life of the engine. This way many will go well over 200,000 without trouble. Often it seems the heads continue to give problems once lifted.
I think this is because they are rarely properly overhauled before refitting. There are several issues to mention in that regard.
Heads may need skimming due to warping. If the warp exceeds 0.07mm the head should be scrapped anyway. As the whole head twists if warped, not just the gasket face, consideration should be given to the fact that the camshaft runs in plain bearings at the top of the head. If the whole thing is warped the camshaft may run out of line and be tight. This is rarely tested for but should be addressed.
If you decide to skim the head the absolute total maximum to remove is 0.40mm. Even then consideration must be given to the fact that the total height of the head, measured from the gasket face to the centre-line of the camshaft must not be less than 139.55mm.
Once the head has been skimmed then there are two things to check.
The valve faces must be recessed below the head face within the limits 0.5 to 1.0mm (inlet) and 0.9 to 1.4mm (exhaust). After head skimming often these limits are breached so the valve seats will need cutting back to maintain the correct recess. Having done this then the effective valve spring pressure is reduced and there is a 0.4mm washer supplied to go under the spring to correct the situation. I also have information that cutting back the valve seats means the valve guide needs cutting back the same amount to maintain the guide face to valve head distance.
Next you need to consider the protrusion of the swirl chambers beyond the head face. This measurement should be in the range 0 to 0.03mm. Again machining will usually be needed to bring these within limits after a head skim.
Regarding head gasket notches. It is correct these different head gaskets are actually to match the piston protusion, not at all related to head skimming.
There can be confusion as to the total number of notches. There are two distinct sets. The notches punched at the centre-line of the gasket are to identify the engine type, they are not related to thickness. For example the 1.7 engine has 1 notch, the 1.9 no notch and the 1.7TD 2 notches. The notches at the rear of the gasket (as it sits on the engine) indicate thickness. The more notches (1 to 3) the thicker the gasket.
Someone could see 5 notches but that means a 1.7TD with maximum piston protusion, not a monster re-skim gasket!
Then after all that you will need a new set of head bolts, a quality head gasket, spot on torque figures and coolant changes every two years....plus an eagle eye on running temperatures. Then the head/gasket will last for ever.
Problem is all the above costs. I wouldn't fit an exchange head costing less than £500 + vat if asked to do the job to a good standard and guarantee it.
As there are plenty of DX 1.9Ds about (whole cars) for under £200 I would look round for a car with poor suspension/tatty but a decent engine, in some ways easier to swap over the whole engine.
We have a spare BX 1.7TD here with an absolute mint engine. Full history since new and oil changes every 3000mls for the latter part of its life. It sounds as smooth as new and doesn't smoke. Never had the head off in 200,000+ miles.
Sorry that's an essay, hope some is of help.
David Woollard
BX Section
Citroen Car Club
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Thanks v much for your considered answer: I suspect my problems began with a mechanic who tested only for the specific gravity of the anti freeze in the coolant, thereby ignoring the need for protective inhibitors every biannual coolant change. It is probably very financially difficult for some self employed engineers working on their own to undertake all the necessary checks and hence continuing problems have arisen.
I will have to consider very clearly the way forward - but the car you mentioned does seem a possible attractive proposition!
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Eh? Bi-annual Inhibitors? Should I be adding these to my 1.9D, if so what are they please?
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Look,time marches on,last week I was looking at a Xantia which my chum had paid three miserable grand for.Not only was it a TD,but it had loads of toys and I couldnt find a mark on it.
Drove like a new car.
Why put yourself through all this hassle and nonsense when you can drive something safer,nicer,and more reliable for peanuts?
there are some great buys out there if you stick to the volume stuff,the rest is still overpriced.
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