Citroen XM Forum

Many thanks Dean and I thought there might not necessarily be a connection between the failed head gasket and scored bore. There were no signs of overheating or reasons that dirt should enter the cylinder to my knowledge and I am fairly sure the only smoke from the exhaust was water. It is strange only one bore is scored, unless there was an overheating or lubrication problem effecting just that end of the block? I actually own a spare engine myself, although I would like to keep it complete if possible and avoid further work to dismantle! Once I have seen the block and obtained further advice I shall make a further post, hopefully including photos. With regards, Matthew T.

its the only course of action really, see for yourself whats going on, to be honest so long as a piston ring has not broken and started destroying the piston and bore i cant see there is an issue.

This is a picture of an overheated engine i delt with last year, note on cylinder number 1 on the far left the scoring on the bore, this was actualy caused by a partialy melted ring groove on the piston, the oil control ring then colapsed and ate its way into the liner, the damage is fairly noticable with deep fingernail catching grooves in the liner, the smoke was rather impressive

CIMG2927 by Deanxm, on Flickr


If yours was driving fine before the gasket went and its not been run out of water then i dont think you have an issue at all.

Good luck anyway.

D

Thanks Dean and it was very interesting that you had a similar problem with only one bore being effected, so perhaps there is also a ring issue in my case? I gather your damage had been caused by overheating, but mine ran fine and I do not recall any excessive smoking or lack of water. Perhaps it would be as well to at least check and possibly replace the rings (if available) and I am reassured you think the issue might not be that serious. With regards, Matthew T.

I called in at the garage on Friday and here are a couple of photos of what I found. The damage to the cylinder liner is luckily quite minor and appears to be a slight surface pitting, which I am confident was caused by the gasket leak that effected the same end of the block. It seems likely that some water must have collected in the cylinder since I took the car off the road about six months ago. I now just have to make a decision about whether to have the valves ground in, which I am tempted not to do, given the engine has only done 120k and with the extra costs involved, although then again it would make sense to do a thorough job! With regards, Matthew T.

Personally I would lap the valves as there can be considerable compression loss from them.

You only get a chance like this once. Its a case of weighing up the extra cost to do everything, with the extra cost of sorting premature problems, or having to pull all out again.

I'd try to do as much as is economically/feasibly possible when you have nice easy access.

Many thanks for your advice Will and Robert and I shall 'bite the bullet' and have the valves ground in as suggested. With regards, Matthew T.

I am pleased to report that the heads are now skimmed, valves lapped and new gaskets and seals refitted by my friendly local garage. Early next week I shall spend a half a day (hopefully) refitting the rest of the engine upper parts, before transporting the lump back home for reinstalling in the car. I have also overhauled the driveshafts and fitted a new offside inner cv gaiter (with help from Dave) and steering rack with two new gaiters and ram sleeve of which photos are attached. Regards, Matthew T.

More photos:

I have been at the garage today putting the rest of the engine back together and I hope to arrange collection and refitting with Dave (the Rave) in the next week-ten days. It will then be a matter of replacing all the ancillaries, including drive shafts etc. and all being well I can remember where everything goes! Regards, Matthew T.