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docchevron
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Post by docchevron »

Yeah, tapping it yourself is easy, and taps are cheap enough from tool suppliers.

The bearing cap itself is just attached to the head with two 12mm nuts, so once the cam cover's off it's a 30 second job to remove it so it may be just as easy and cheap to take it to a machine shop..
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Post by MULLEY »

Didnt realise the bearing cap was attached by just a couple of bolts, i will have a look one evening to see if i can work out how to remove. Cheers guys.

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Post by docchevron »

Tis easy mate, once the covers off, remove two 12mm nuts, tap gently with copper hammer, off it pops. Jobbed.
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Post by MULLEY »

Tonight i took the rocker cover off, cleaned that up a bit, started getting the gasket silicone off the rest of the cam bit of the engine & noticed on the end bearing cap near the cambelt that there was something sticking out from it.

So took the bearing cap off & to my horror it would appear that the bearing cap has gotten damaged & this has caused it to rub onto the actual cam itself which has cut a thumbsized width out of the cam. There were a few largish bits of metal that i pulled out of the cam as well.

This doesnt look good???? what are my options regarding this, can i just refit the existing bearing cap & due to the damage wear on this & the cam then it probably wont foul each other anymore?

or should i replace the bearing cap & also replace the cam???

I took some pics of the bearing cap & the bits of metal i pulled out, didnt take one of the cam as the light is a bit shite, but will take a photo tomorrow.

I will try & put these pictures up, once i find that pesky thread on how to do this.....bloody car :evil:

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Post by MULLEY »

Image

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Image

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AndersDK
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Post by AndersDK »

WTH ???

Something is rotten in the cam area :shock:

Should NOT be possible for the cam to rub against a bearing cap :!:
Either it has been fitted the wrong way around, or cap is not the correct type for that particular position, or the endfloat shim is missing or heavily worn.

Haynes is pretty good on this issue, shows a couple of pics and schematics on this area.
C U / Anders - '90red16riBreak - '91GrisDolment16meteor - Project'88red19trsBreak
dead cars : '89white 16RS - '89antrasitTRDturboEst - '90white19triBreak

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Post by jeremy »

Is this what happens when someone bodges repairs after a cambelt problem resulting in a broken camshaft.

Is this bearing ca[ from another engine - so not line bored etc (The wear surface in the middle of the cap - with dirt either side suggests that it was only contacting on that part.)

As there is no bearing fit - there is no proper lubrication as the can be no proper oil film. Partial siesure has taken place and basically the camshaft has skimmed a layer off the cap which is some of thr rubbish you have found.

Looks like another head to me with a really good clean of the rest of the engine to find any other bits there may be.

Line boring - the name given to the process of boring the bearings and caps - assembled - so that an accurate hole is made in all caps - for the camshaft. This means that bearing caps cannot be interchanged between engines and the only repair can be made from a blank - which then has to be line bored.

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Post by MULLEY »

Ive no idea what has happened to this engine in the past, so unable to answer your questions. So my understanding of what you said is that the bearing caps are designed to exactly match the cam thats fitted?

The cam is damaged also where its seized as you called it. Er how much will this little lot cost? :(

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Post by jeremy »

The head and assembled bearing caps are bored as a unit - to get them straight etc. They are bored to a standard size to allow a standard camshaft to fit.

The camshafts are interchangeable - the top parts of the bearings are not. (even on the same engine - and must go in their original places.)

The easiest (and probably only) repair will be to get another head.

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Post by docchevron »

hhmm, thats a mess!
Sorry mulley.
If you can find another head that may be the easiest answer.
If the car was in my shed, I'd re-cam it and put a new bearing cap on (and line bore it).
But since it aint, anyone got a head??
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Post by MULLEY »

What would be the consequences of just re-fitting as is??

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Post by jeremy »

Who knows!

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Post by MULLEY »

Here is a picture of the cam with associated wear :(

Image

I guess there are 2 ways of looking at this, if i hadnt been useless & stripped a part of the bearing cap i would never have known that this problem existed, so i guess its probably a good thing that i know, albeit frustrating as i now dont have a car of my own to drive....

The other side is that i would have been blissfully unawares until bang crash wollop (not sure how to describe an engine eating a cam)....so i think i would rather know now than later & possibly more expensive damage.

So, does anyone have a spare head lying about that i could purchase please???? oh, & does it have to specifically come from a 1.7 turbo?

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Post by AndersDK »

I believe a standard BX TUD head woud readily fit, but the cam must come off a 17 variant.
Note that the old Visa model continued for years as the C15 van, fitted with the XUD7 diesel variant. This could be a donor for the head.

TBH I dont think you should run into trouble sourcing a head for your BX.
I know that the later Xantia 19TD's may be easier to find, but dont think they are a direct swap. Some of our onboard diesel heads will know for sure.

And then we have not yet talked about the Peugeot variants with same engine type ...

Hope thats a pat on your shoulder to get on with a smile on your face :wink:
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Post by jeremy »

Anders - presumably the reference to a TUD means that you have been looking at something more interesting?

The XUD diesel head has 120 degree inlet valve seats - the turbo has 90's. There are some dimensions in Haynes Diesel manual - which can be downloaded here:

http://sitruuna.unk.fi/pub/korjausoppaat/

I think there may be metal alloy differences between a N/A head and a turbo one. I have heard it said that later Xantia ones are stronger.

Mulley I can't imagine why your engine has tried to eat its camshaft. A good and ingenious engineer might be able to save the head but the work would be enormous - and expensive.