Having to rebuild the engine

[paul001]

Sadly the time has come to rebuild my engines top end as I went towing last weekend, all the engine could kick out was 40mph @ 5000rpm. The mayo I previously reported has got worse and I'm finding oil in the water, I know this is bad.

As the engine possibly has never been touched can you give me some pointers of the danger areas? Other than below

I am aware it is a wet linered engine so instead of levering the cylinder head upwards to release it I know I need to rotate it instead to hopefully no disturb the liners.

I have decided to rebuild rather than replace because the engine has done a genuine 70k and has full service history from the garage where it was a courtesy car.

cheers chaps

[DavidRutherford]

Remind us... which engine do you have?

If it's a 16 petrol, then I have a perfectly good low-ish mileage engine you can have for free here. Far easier just to swap for a known-good unit than do a re-build.

... or even just chuck this engine in and then rebuild yours at your leisure rather than have the car off the road...

[paul001]

I have a 19 GTI D6D XU9J2.

[Tim Leech]

Paul there is a guy on ebay with a 19GTi (albeit auto) with less than 60k on that hes breaking and the engine is for sale, ive had some bits off him and he seems a decent bloke. As david says its probably cheaper to buy a good used engine and he will take it out for you, maybe worth looking at?

http://cgi.ebay.co.uk/CITROEN-BX-GTI-AU ... dZViewItem

[citronut]

i would check your oil cooler first as its far easyer than head off or engine swap, if your very lucky your bad running might be something more straight forward like plug/leads coil/s, or even cam timming

regards malcolm

[Vanny]

oil cooler, on a BX? Do you mean the water heat exchanger that fits between filter and oil filter? Cos if not i'm interested to know what BX's have an oil cooler, could be a good find!

[paul001]

It's not the plugs/leads/cap etc as these have been replaced I believe it is far more likely to be the head gasket on the way out. One of my college tutors have told me that the XU series engine suffered badly with leaks from a failing head gasket

I could be tempted by an engine to rebuild, wouldnt want to remove mine to replace with an unknown condition engine so I will dry dock the car for a few days to rebuild the top end of the engine

[DLM]

One of my college tutors have told me that the XU series engine suffered badly with leaks from a failing head gasket

With all due respect to your college tutor, I suspect he may have a prejudice against wet-liner or XU engines, possibly through bad experiences when having to repair them or explain failures. Ask him why XU head gaskets might fail, not whether they do.

We all have our prejudices. Some are caused by having to deal with the effects of a particular kind of failure. The original causes can be something quite different.

None of the XU or XUD engines in BXs I've owned since 1992, including a 19TRi, have suffered this way, except when the cooling system's been neglected at some point in the life of the car (and then, only on couple of the diesels I've owned - which don't have wet liners). Even legions of Peugeot 205Gti-thrashers have struggled to kill their XU engines this way, except through abuse that would kill most engines too.

I've been through head-gasket paranoia on my own cars a couple of times - it's a nasty obsessive feeling that won't go away easily and holds you back from logical analysis of problems.

A critical thing for any XU is coolant changes at very specific time-intervals with the right mix of corrosion-inhibiting antifreeze to avoid internal corrosion in the coolant passageways within the engine. If such corrosion has occurred, you'll probably find traces of it soon enough if your dismantle, though I'd expect to first see it in the colour of your coolant.

Have a look at this thread

http://www.bxclub.co.uk/forum/viewtopic ... sc&start=0

if you haven't done so already - apologies if you have done so. Yes, I know it's a carb-fed 19 model here, and I believe the mentions of an oil-cooler may be a red herring.

The general informed consensus on this forum is that wet-liner problems or gasket problems on XUs - if they do occur - are most likely to be pretty explosive in nature. You'd know about it pretty soon through overpressure, the ever-upward movement of your temperature gauge, or something worse! At least you've GOT a temp gauge to look at, unlike the owners of many other BX models.

A compression test on the engine could confirm head-gasket probs, but some combination of coil , oil-breather blockage, or clogged-up exhaust system could equally well contribute to the driving symptoms you're describing - in my opinion.

A low-miles engine driven mainly in town is very prone to condensation (hence mayonnaise), then breather blockage and also top carbon-build-up in the exhaust system and elsewhere. Your car might be struggling for breath rather than incontinent.

Good luck, whatever you decide to do, or are already doing! I'd be very happy to be told I'm barking up the wrong tree - or just barking...

[paul001]

I understand when you're saying about blocked breathing systems It could be a blockages in the system somewhere as every now and then there is a nice cloud of blue smoke with a nice odour of burnt engine. Another thing that may point to a blockage in the breathing system is every now and then the car seems to have a flat spot it doesnt cut out or anything just looses power for a brief moment but is very noticable and I have had the injectors cleaned professionally also running a cleaner through every 5000 miles

Considering a compression test do you know the range of figures I need as I havent found them in a haynes or similar when ive been in the local parts shop.

[citronut]

oil cooler, on a BX? Do you mean the water heat exchanger that fits between filter and oil filter? Cos if not i'm interested to know what BX's have an oil cooler, could be a good find!

Vanny
yes i did mean oil cooler and yes it is the unit the filter sits on, and yes BX's do have one, and XANT people/owners are have oil cooler faliure's were they break up inside (no not the owners), hence oil and coolant mixing

regards malcolm

[tom]

Hmm. THe cutting out may be due to the ignition black box. Does it run on all four? If so, I'd expect it o do more than 40 (unless, of course you were towing a cross-channel ferry.) Mayo in the top isn't always a sign of impending doom Blue smoke on this engine is usually valve guide oil seals.
What to do. Roll the car on a level surface, to eliminate binding brakes.

Check thoroughly that no plastic engine pipes are split, or have dropped off. Check that all the ignition bits are clean. Listen to the engine at idle and decide whether it sounds healthy. Will it rev cleanly from idle?.
Before going in mob handed, Let's between us find a more solid diagnosis than your lecturer's guesswork. XU petrol engines seldom have either head gasket or liner issues so let's rule out the sillies before pulling the engine out, which is a job best avoided if possible.

[paul001]

Definately not binding brakes, it might have been in the past, I have just fitted new discs and pads all round.

Could be the black box I'll get it checked when I come back from holiday and replace as necessary.

[mat_fenwick]

Sorry to sound pedantic, but when you say it's not binding brakes is that because you have just changed the discs and pads; or because you have just changed the discs and pads and checked that the sliders aren't sticking? Just because the discs and pads are new does not necessarily mean that they aren't binding, although in this case I think it sounds unlikely.

Compression figures - I don't have any specifically for the XU, but as a guide I would expect in the region of 175 psi. There is a formula to calculate the maximum expected pressue from the compression ratio, but it has slipped my mind at the moment. More important to check for consistancy between cylinders, ideally no more than 10% variation.

[citronut]

have you checked the cam timming and ignition timming

regards malcolm

[paul001]

Cam timing has not been checked will be checking when i get back from hols as the car needs a new belt