HDI back from the dead!

XantiaJon · Post by **XantiaJon** » 24 Mar 2006, 13:54

Follow up to my previousPost subject: XANTIA HDI DEAD!

New rocker arms fitted, new Cam Belt & Tensioner fitted! All done without removing the head! Running a treat sounds great! Just waiting for the bill! I really thought the car would be uneconomical to repair.
Now I just need the cover from the Cam Belt as my ones got a big hole in it where the tensioner came out! Anybody got one for sale?
Thanks to everybody who posted, especially Kowalski.

Posted: Thu Mar 16, 2006 5:32 pm Post subject: XANTIA HDI DEAD!

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My 90 BHP, HDI cam belt tensioner, disintegrated! I was driving at high speed (100 mph +) at the time! Now my engine is shot! Anybody know how much damage is likely to have occurred? The cam shaft pulley rotates with virtually no resistance! I've got 3 options, Scrap it, have the head taken off & hopefully have the damage fixed, or have a 2nd hand
engine fitted. Anybody used Tower engines in London?
My Xantia is W APRIL 2000, is it worth fixing!
Anybody want to buy it for parts LOL? It's just clocked over 71K, New spheres fitted a month ago
Posted: Thu Mar 16, 2006 5:32 pm Post subject: XANTIA HDI DEAD!

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Honda · Post by **Honda** » 24 Mar 2006, 14:30

Congratulations!

What differences should one expect between (1) petrol, (2) old diesel, and (3) common rail engines if the cambelt is blown while driving?

ACTIVE8 · Post by **ACTIVE8** » 24 Mar 2006, 14:42

Great news !

Well done.

Pleased to hear that you got your car going again.

Post by **Peter.N.** » 24 Mar 2006, 14:45

Well done! Thats got to be an improvement on the XUD!

James.UK · Post by **James.UK** » 24 Mar 2006, 15:41

Nice one Jon and Kowalski

.. Once more the forum members save a Citroen from being scrapped.

Is it possible to swop the HDI type rocker arms with those fitted to the XUD engine? If it can be done, then I think it would be a good idea for ZX-XUD owners to do the swop!

reblack68 · Post by **reblack68** » 24 Mar 2006, 16:15

Honda wrote:Congratulations!

What differences should one expect between (1) petrol, (2) old diesel, and (3) common rail engines if the cambelt is blown while driving?

Some petrol engines are designed to be "non interference" and can break a cambelt with impunity. Diesel engines cannot be designed this way because of the higher compression ratio, the piston has to come too far up. Traditionally a broken belt on a diesel has been a disaster. It seems that the Hdi engine has been designed to limit the damage- this was news to me. I've heard of other diesels, the old Transit engine being one, that also bend stuff you can fix easily.

Sadly the XUD cam acts directly on the valve (via a shim and bucket) so it can't easily be modified in this way.

Kowalski · Post by **Kowalski** » 24 Mar 2006, 16:36

James.UK wrote:Is it possible to swop the HDI type rocker arms with those fitted to the XUD engine? If it can be done, then I think it would be a good idea for ZX-XUD owners to do the swop!

Not possible I'm afraid.

The heads are rather different between the HDI and the XUD and the parts are just not interchangable.

My understanding is that the HDI engine operates its valves via hydraulic tappets and rocker arms where as the XUD operates its valves more directly with the cam above the valves.

When the valve gets forced upwards on an XUD its the cam it is being forced against, the cam is fairly strong but the crank is a lot stronger so the cam and its bearing caps get broken, the valves bent and possibly the head gets damaged too. With the HDI the valve is pushing against a relatively weak lever so that breaks easilly and the valves + cam can escape relatively undamaged.

These two pictures are of XUD heads.
http://www.kouvolanmoottorikoneistamo.fi/images/200.jpg
http://www.kouvolanmoottorikoneistamo.fi/images/256.jpg

And this is an HDI rocker arm.
http://groups.msn.com/honestjohn/proble ... hotoID=156

Honda wrote:Congratulations!

What differences should one expect between (1) petrol, (2) old diesel, and (3) common rail engines if the cambelt is blown while driving?

Differences between petrol and diesel? Diesel engines have higher compression so there is no (or very little) clearance between piston and head when the piston is at TDC. Petrol engines are mostly multi-valve now (more than 2 valves / cylinder) and very few are non-interference designs, there is more clearance than on a diesel but because of the way multi valve engines have the valves at an angle rather than being vertical you tend to get bent valves (and broken valve guides) rather than the catestrophic damage that and XUD will do to itself.

There is no difference between common rail and mechanical injection diesels in terms of breaking themselves when the timing goes. There is a difference between direct injection and indirect injection (common rail engines tend to me indirect injection) in that direct injection engines have lower compression and thus more clearance but these engines are by no means not interference. The trend is for diesels to go multi-valve the way petrol engines did, this is going to mean bent valves on the 16 valve HDIs I would expect, rather than broken rockers that you get on the 8 valve HDIs.

Honda · Post by **Honda** » 24 Mar 2006, 16:44

The XUD may have its limitations but it's indeed a tough engine if well taken care. I have been in a XUD 1.9 with 700.000kms that was still working as a precision clock and, according to owner, almost so economical as first day.

Stewart(oily) · Post by **Stewart(oily)** » 24 Mar 2006, 17:07

Great news

have to keep a lookout for cheap HDIs now.
Stewart

Post by **Peter.N.** » 24 Mar 2006, 19:47

The 2.1 td XUD has hydraulic tappets and rockers, I've never heard of a cam belt breaking on one of these, has anyone had experience of that happening, what was the result?

f00lzz · Post by **f00lzz** » 29 Mar 2006, 23:56

Xantia 1.9TD after auxillery belt entered cambelt cover and snapped the cambelt... I have more pic's if this one isn't upsetting enough

Bigjoe · Post by **Bigjoe** » 30 Mar 2006, 09:28

Before it died at the hands of dozy woman in a golf,i had a Peugeot 406 1.9td 1997 that had done 278k miles,on one of the rare occasions that my dad drove it,it snapped the camshaft into 3 pieces,but the timing belt etc was still intact!? so i rebuilt the top end and checked the block and the block was in beautiful condition,thats why i want a 1.9td xantia estate,as i know the citroen/peugeot diesel engines are bulletproof

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