Pre-Combustion Chamber Cracks -ZX1.9D

Andrew Robey · Unread post by **Andrew Robey** » 10 Feb 2004, 20:21

Have just had the word from the engineers pressure testing my ZX1.9D head, who say that there are cracks in one or more of the pre-combustion chambers, and it was this that was causing my cooling system to be pressurised.[:(]
Being formerly a petrol-only DIY-er, this is new to me, but I'm advised it is fatal. Is this true? Could they be mistaken?
They want £140 to put new chamber linings in, but to be honest with the cost of gaskets, bolts etc I'm inclined to replace the engine (local scrappy has one from a 75K C15 van, fitted for £200)
Any help please [?]

CITMAN · Unread post by **CITMAN** » 10 Feb 2004, 20:35

i think these cracks are normal on the xud and doubt that they would effect your cooling system. i think they are trying to milk more money out of you. Dave burns will know more about this than me.

AndersDK · Unread post by **AndersDK** » 10 Feb 2004, 20:44

These cracks can be observed with head of on all diesels. They may be from hairline cracks barely seen - to the fatal cracks killing the head.
Why these cracks develops I donno - but it must have to do with the inherent principle of the combustion that starts in the pre-combustion chambers - and then extremely hot gasses racing out to the cylinder cavity as combustion pressure rises.
You have the usual dilemma on an elderly car : repair or replace.
Points to reflect on are :
1) you know your present runner pretty good - either for good or bad.
2) a s/h engine is "like new" if you ask any breakers - as long as it starts and runs for a test.
3) consider a recon head - at least this have been tested for any other severe problems - which may still be hidden on the present one - and you have a warranty. The job is then a throw on with new gasket & bolts - no hassle with repairing the old head & possible mishaps from the mechanic.

jeremy · Unread post by **jeremy** » 10 Feb 2004, 21:33

If the problem is the pre-chambers then I'd have thought £140 to cure the problem was very reasonable. As Anders says there may well be more wrong with a second hand engine. The BX TD engines are very prone to cracking generally with age but I believe the ZX 1.9 Td to have been made differently and I'm told the head is thicker - so your cracking may well be confined to the pre-chambers.
The chances are that your specialist is right - after all he is not going to want to do the job a second time at his own expense is he?
jeremy

Andrew Robey · Unread post by **Andrew Robey** » 10 Feb 2004, 22:15

Hmmmm. Had a more detailed chat with the Gaffer. Apparently the cracks, which he agrees are normal on any diesel, have extended beyond the firing ring on two of the cylinders, so although the head is flat and passed the pressure test, skimming and a new gasket would be no use.
As the test is visual, I'm a bit narked that they didn't do it BEFORE the pressure test and save me £20 quid!!
Previous comments taken on board, but still think I'll go with the s/h engine....