This is regarding the engine on my Jetta, but since there's a number 
of diesel bus owners out there, I thought it might be useful to post 
and (hopefully) get some feedback.

Here's the story: 
I've spent the last 3 nights replacing the head gasket on my 1.6 
turbo diesel, after getting tired of explaining why I leave my oil 
drain pan under it in the garage. I'd been putting it off since it 
seemed to be running better than ever, and mileage was great (1000km+ 
per tank lately).

Anyways, last night I put the head back on after spending a few hours 
cleaning up the valve area & piston tops. #1 & 4 had quite a buildup 
of white crusty stuff, although #2 &3 also had some. Crusty stuff was 
on both the piston and the comb chamber area around the prechambers. 
On all but #4 it scraped off easily, but #4 left some pitting in the 
piston and head.
Can someone tell me what this stuff is? I suspect it may be from 
coolant leakage, although I was never really sure if the head gasket 
leaked coolant or not, since it ran fine. I was losing some coolant, 
but my water pump gasket (installed by someone else $$^@$#^@) has 
been leaking, so it's hard to tell.
Could this stuff be somehow related to the pump timing being off? I 
adjusted the pump myself according to the book, except using the 
listen & drive approach, instead of the expensive tool. (This was 
done a year ago, and engine seemed to smoke less afterwards).

Also a question on the head gasket: the new one I got has two 
additional holes for water passages at the front of # 1 & 2 cyl which 
line up with the block & head. The old gasket had *no* holes here, 
ie: it had 4 holes for cyl #3 & 4, but only 3 for cyl #1 & 2. Does 
this seem strange?

Shawn
'88 Westy 332k (Kyra)
'85 Jetta TD 350k (Jenni)