Off with it's head!

tomsheppard · Unread post by **tomsheppard** » 13 Jan 2003, 16:49

The verdict on the BX (19TGD for those who haven't yet been bored to death with my postings) is that I am going to have to pull the head off and replace the gasket. My local garage who have experience in these things reckon that this is a straightforward replacement and I shouldn't need to skim or pressure test the head as it is only a minor gasket blow. The car certainly performs all right. They want a lot of money in BX terms so I am contemplating DIMyself, reckoning that If I don't have to strip the whole head down, I can probably tackle it without the time/frustration index becoming too much.
Has anybody tried it? Has anybody succeeded?

Unread post by **RichardW** » 13 Jan 2003, 17:29

I've done a TD - and that's a pain. Non turbo should be easy. You just need a 16mm deep socket to get the engine mount off (i used a spark plug spanner), a selection of 3/8" drive extensions to turn back the timing belt tensioner, and a T55 socket to do up the new head bolts. About 6 - 8 hours I'd guess, as long as you don't hit too many snags!
Richard

tomsheppard · Unread post by **tomsheppard** » 13 Jan 2003, 17:38

Thank you Richard for your encouragement. I see that you make no mention of the crankshaft pulley. Does it all come apart without having to undo this?

hippy · Unread post by **hippy** » 13 Jan 2003, 17:43

I've done it too to a turbo and it was fiddly but not too bad...was out there in the cold Jan without a hoist too..the wing tooak a small scratch but it was ok. Unfortuneately my problem was porosity and not the head gasket but she got running again anyway until I managed to get the problem fixed...how do you know you haven't got porosity too? It may be worth a test (around £35 if I remember) just to save you lots of hassle
You may need a big torx socket which I can send you in the post if you need it but a new one may not be too expensive
Make sure you get the correct head bolts (always use new ones) as some are just torqued up and others are tourqued and then tightened by further 15 degress or so
good luck!!
FYDAMF

Unread post by **RichardW** » 13 Jan 2003, 17:57

Tom,
I just let the tension off the belt and let it sit there still around the crank pulley, so I didn't have to take the crank pulley off. Just pull the belt up carefully when refitting to make sure it engages with the crank sprocket, and turn the engine over by hand a few times with the covers off to make sure the belt is working OK, and not riding off the sprokets at all.
Oh - you'll need 3 off M8 x 40 / 50 bolts to lock the cam and injection pump, and some way of locking the crank - I found that a long piece (I bought a 1m length I think) of M8 threaded bar was ideal (I'd have preferred solid bar, but could only get threaded locally) - bend about 3" of the end up to about 30 degrees, and this will allow you to wiggle the bar into the hole into the flywheel whilst you are standing by the drivers wheel, turning the engine over with the wheel, and inserting the timing bolts - saves a lot of walking backwards and forwards!
Richard

Simon Canfer · Unread post by **Simon Canfer** » 13 Jan 2003, 18:01

I did the head gasket on my ZX TD; first one I'd done on a car and it wasn't too painful. Best advice I can give is to take it slowly, don't skip anything as it's not a job I'd choose to do again in a hurry. Consider replacing other accessible items while you're there; like the water pump and cambelt tensioner pulley.
I found I had to make a very slim socket driver to fit down between the cambelt components and the inner wing (whether this applies to the BX I couldn't say).
The good news is mine only needed a gasket; symptoms were over-pressurisation of the cooling circuit but otherwise nothing.
Simon Canfer
Join the Citroen Car Club!

tomsheppard · Unread post by **tomsheppard** » 13 Jan 2003, 18:03

yippee! after all the hassle of busted bolts last week, I wasn't looking forward to cracking that one off. I guess that porosity isn't the problem because I have constant air bubbles in the cooling system from start up and the pressure is maintained overnight. I reckon that porosity would not allow the pressure to remain.

Unread post by **RichardW** » 13 Jan 2003, 22:05

Having said all that of course, I forgot to mention the fact that I knew my cambelt had been changed only 20k miles/1 year before I did the gasket, so I knew it didn't need doing again. If yours is coming up, or you do not know its history then it's worth changing it whilst you've got most of it dismantled anyway.
Richard

mg46783 · Unread post by **mg46783** » 14 Jan 2003, 05:17

Hi ...... just feel the urge to add my ten bobs worth..
Simon I think it was said, quote ", don't skip anything as it's not a job I'd choose to do again in a hurry. Consider replacing other accessible items while you're there; like the water pump and cambelt tensioner pulley.".....unquote Wise words....its a lot of work in man-hrs and money down the drain in parts if you should screw it up.. big shame if its down to cutting corners.
My advice would be to, 1. have the skimmed regardless - 2, have it pressure tested regardless... 3, use new bolts ( as well as the obvious, head gaskets etc ....) I would also advise using a genuine head gasket as opposed to a spurious one.. and 4, I would fit a NEW timing belt....whatever the age of the "old" one... the idea being - they dont tend to like re-tensioning...and nor do some of the pulleys/water pump etc......I would check them v-e-r-y carefully.
As I say, its a lot of work... you dont ( I wouldnt think) want to risk doing the job twice, for the reasons stated, so whilst its more money doing the things above - you could well save your self a lot more money - and time - in the long run. Its obviously up to you but that as I say , is my 50peeees worth.
Mike
ps. timing belet makers...cant spell manufacurers, always say never to refit a belt once its been used! ( and no, I dont sell them! )

DLM · Unread post by **DLM** » 14 Jan 2003, 06:12

I've just done a practice run, removing the head from a 1.9D non-runner, and would only add a (Welsh) couple of things to what's been said already.
(1) Make sure your tools allow sufficient clearance in the space between engine and inner wing, as someone has already pointed out.
(2) If they don't then look again and see if you will have sufficient clearance to do what you want if the upper engine mount is removed (trolley jack with wooden plank needed under engine as recommended in Haynes etc).
(3) Make sure you remove the front-plate bolt which fits horizontally into the head, hidden under the timing belt and upper engine mount. I missed this bolt when I first tried to lift the head. By the front-plate, I mean the vertical plate on which the injection pump is mounted, to the right of the timing belt. It's probably in the Haynes instructions, but I wasn't referring to them at the time....
(4) Do check the head for cracks visually - there's a nice photo-feature on XUD head gasket replacement in an issue of Car Mechanics from about a year ago when their project-car 405 diesel blew its gasket - probably still available as a back number.

tomsheppard · Unread post by **tomsheppard** » 14 Jan 2003, 14:45

Thank you everybody for your advice. The beast willl need a new cam belt soon but as the whole saga is a rather speculative venture anyway, I will first change the gasket. This represents the least time and money approach to sorting out the fault. If the problem is not solved then the head is porous or cracked or warped or otherwise expensive and time consuming to fix. Stripping it down to have it skimmed and pressure tested and then rebuilding and reshimming etcetera- it is just too much hassle.If upon inspection, it is cracked then I know why there is a fault and I then have a sporting chance of getting it fixed with a second hand head. If on the other hand, the engine retains its coolant after a simple(!) gasket job then it is worth replacing the cam belt and spending a little money on it. After all, I will at least be able to get the engine up to temperature so I can remove the crank pulley bolt...

tomsheppard · Unread post by **tomsheppard** » 20 Jan 2003, 15:29

Firstly a big Thank You to all who have contributed on this thread especially Dave Burns for a correct diagnosis, Dave Woollard (methods of exorcising air) and Jon for his constant Brainracking on my behalf. Once the head was off, it became apparent that number four was blowing. It had a beautifully steam cleaned combustion chamber!
I didn't find any cracks (save for a couple of little ones in a prechamber which I'd been expecting) and I cut slots down an old bolt to tap out the threads in the block before using new bolts with a trace of copper spray grease. Glitches? Refitting the downpipe to the manifold is difficult from the top and if I ever do it again, I will use ramps and refit the bolts from below! I couldn't pin the flywheel,even with 18" of custom bent, rounded ended, 8mm stainless steel super tool, so I had to pull the starter motor off which meant that I had to disturb the clutch linkage. I got my revenge on the latter, though with plenty of grease:-)I made up the very king of header tanks with a fork gaiter from a motorbike to fit over the filler neck and a 2 gallon plastic container glued onto it with a strong sealant. Forty minutes after an uneventful restart during which I pumped the primer as I turned the key, the radiator was hot all over and although the fan hasn't cut in yet (it is cold around here) I am not worried because the switch is new and the fan works when the switch is shorted out. The best bit though is that the coolant level is just that - level at last! Fifty miles of testing ranging from flat out to half an hour in traffic without problems seems to suggest that it is fixed. I propose to run my own rad flushing programme over the next month, A capful of Flash liquid which doesn't foam in the coolant and drain it weekly before deciding whether I need a new radiator. My man at the accessory shop asked facetiously if I used Pine or Lemon. The answer was of course obvious.

Unread post by **Jon** » 20 Jan 2003, 17:07

Lemon, naturally.
I would have thought that went without saying.
Jon Wood
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