Xantia Head Gasket

49er_Jerry · Unread post by **49er_Jerry** » 04 Sep 2010, 11:10

'97 Xantia 1.9 Turbo Diesel

The HG on my Xantia is on it's way out and needs to be replaced. Blue/White smoke, misfire, oily coolant, high coolant usage etc. Silightly annoyed because a local garage did the job 2 years (25K miles ago), so have decided to do the job myself. They claimed to have skimmed the head, but cannot be sure.

I have found various old threads talking about the job. This one seems to be the most comprehensive. Are there any others that are worth a read before I begin.

Also, before I begin the strip down, are there any tools that I should aquire prior to begining. Will also change the timing belt at the same time. New CH bolts and Crank shaft bolts. Will I be able to identify the correct CH bolts before I begin. Similarly, should I remove the head before getting the replacement gasket. Check the number of notches etc.

Any views would be gratefully received.

citronut · Unread post by **citronut** » 04 Sep 2010, 12:24

the usual sign of H/G faliure on these engines is the coolant over presurissing and gushing out of the header tank,

although it is possible to have the symtons you have,

oil in the coolant is usualy the oil coolerleakind into the oil way internaly,

i would thoughraly check all other possabilaties before going the H/G route,

maybe you have more than one fault

regards malcolm

49er_Jerry · Unread post by **49er_Jerry** » 04 Sep 2010, 12:26

Yes, I didn't mention that the coolant is pressurising. Gases are clearly visible escaping from the filler reservoir when the engine is started from cold and the coolant level filled. Regular big bubbles also coming out of the reservoir too.

The cooland doesn't gush as such, but takes about 2 litres to top it up to overflowing in the morning.

The temperature fluctuates when running between about 70 and 85 deg, judging from the temp guage.

Unread post by **Old-Guy** » 04 Sep 2010, 14:41

The link Jerry posted is to a more restricted discussion about what tool to use to retract the tensioner. I've since made a better dirt-cheap tool.

I know others will disagree, but you can significantly reduce the risk of the head needing a skim by 'un-torquing' the head-bolts in the same manner and sequence as for tightening. The key point is to undo each bolt by exactly one flat in sequence, repeating the one-flat-in-sequence until they are all loose.

Since a blown head-gasket is almost always the result of over-heating, change the thermostat while you're at it - often the unsuspected cause.

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 14:56

The heads have inserts in them which are made of a very hard material which does not like being machined. These inserts are also very hard to get out so are often left in.

I know this as I am a proto-type automotive machinist, and have skimmed the odd XUD head for colleagues at work aswell my own.

With the right knowledge, patience, cutting tool and cutting oil the skimming can be done well with these inserts in-situ.

I am thinking that although the garage said it was skimmed, finding a machine shop willing to do the job properly at the right price might of been beyond your local garage so they might of told you a porky or two, hence why it has gone again only 25k miles on.

If you are close to Brighton/Worthing in Sussex I'd be willing to skim it for you.

Cheers,

Shaun

Unread post by **Old-Guy** » 04 Sep 2010, 15:01

Shaun, is it impolite to ask if you work for the company that originally developed the XUD?

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 15:11

Of course not, I work for Ricardo (www.ricardo.com) we have done extensive development/testing on the XUD over the years, not sure if it was entirely when the engine was at prototype stage or for future emissions/durability/power upgrades.

There probably is'nt an engine type, or automotive technology that Ricardo have not had a hand in at some stage.

Shaun

Simon99 · Unread post by **Simon99** » 04 Sep 2010, 15:21

Maybe worth considering adding a bottle of K-seal gasket repair or similar to the coolant if that is the main problem. My 1.9TD was drinking coolant at an astonising rate but after adding the K-seal problem solved. 18 months later still just fine.

They do advertise it as a permenent fix.
Think someone makes similar additive for oil as well but not sure.

Unread post by **Old-Guy** » 04 Sep 2010, 15:34

I've seen it suggested that the reason why the XU series engines use some very unusual metric sizes is that the original design was a Ricardo project (for a UK/Scandinavian customer) that was cancelled at a late stage. Consequently, the design was to imperial standards. But when PSA bought the design, the conversion to metric necessitated using some unusual sizes to get some fasteners into the available space without making significant design changes.

So according to this version of history, the XU (and particularly the XUD) designs aren't French at all, but a triumph of British engineering!

49er_Jerry · Unread post by **49er_Jerry** » 04 Sep 2010, 15:39

Shaun, Thanks for the offer. Sadly though, I'm in Sheffield. So, quite a long way to travel.

Will try some K-Seal as suggested. Is it available from Halfrauds / general factors?

Still have a feeling that I'll be changing the gasket at some point.

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 15:46

Thats good to know.... I will ask some of my older and wiser colleagues and find out our history with the XU's.

Well British engineering is still alive just not on the same scale of yester-year.

If the HG is gone again I reckon its warped or has never been skimmed and needs it doing hence why it has gone again!

Good luck.....

49er_Jerry · Unread post by **49er_Jerry** » 04 Sep 2010, 15:58

Is it worth trying the K-Seal option then, or just getting on and changing the HG and getting the head skimmed.

Anything I need to tell a machine shop to get it done properly?

MikeT · Unread post by **MikeT** » 04 Sep 2010, 16:00

I wouldn't recommend using a "sealant" if you're going to repair the gasket but it's your car. The problem being, the sealant is indiscreminent(sp?) and will clog fine passageways if possible. It's designed to adhere itself to metal and will not flush out readily.

Here's a head gasket guide for calculating thickness

I would advise buying a head gasket kit and new bolts. I took the easy route and bought the thickest MLS gasket. The machine shop didn't flinch when they saw my head had precups, they just skimmed it (and they kindly removed the valve stem seals for me as I didn't have the right tool) for £40 all in.

Don't throw the old head bolts away, they have two uses. If you cut a tapered valley down the length of the thread you can use it as a thread cleaner/chaser. If you cut the head off, you can use it as a locator when refitting the head.

For what it's worth, my own endeavours were blogged here

49er_Jerry · Unread post by **49er_Jerry** » 04 Sep 2010, 16:18

Thanks Mike. I tend to agree with you. Just read the K-Seal website and it doesn't sound like a the correct solution (excuse the pun).

Will have a read at you link. Are there any 'crux' points I should be aware of?

shaunlfc1 · Unread post by **shaunlfc1** » 04 Sep 2010, 16:20

Well the easy cheap option is the K-seal, worth a try before you go for full open heart surgery.

As for machining, it best to use a carbide tipped cutter that is bigger enough to cut the full width of the head in one go. Other wise a smaller cutter and multiple passes can leave steps which is no good. This is very likely if the machine is anything less then a precision tool-room mill.

The hard inserts will simply chip a High speed steel cutting tool or single point carbide tip that doesnt have a substantial cutting radius on the end.

Plenty of cutting oil/coolant to keep the rock hard bits of insert swarf away from the cutting tool. The cutting tool easily picks the swarf up and drags it across the freshly cut combustion face giving a very unwelcome deep scratch.

Does'nt sound hugely scientific but hope it helps in some way, any machine shop worth its salt will know all that or have even better methods!

Good luck!