OT: rabbit diesel - water in cylinder #1

[drew at scirocco.cs.uoguelph.ca (Drew MacPherson)]

On Sun, 26 Oct 2003, T. Reed wrote:

> So what's the diagnosis? He complained that the car has been loosing
> coolant; about a cup every 10 miles. He found a hole in the bottom of the
> radiator and epoxied over it as a temporary fix; but it has still been
> losing water. It wouldn't surprise me if the car has been overheated at
> some point in the past..

Water in the combustion chamber is a blown head gasket or a warped/cracked
head.  If the cars was overheated, then either (or both) is a possibility.

> I'm thinking the head gasket has failed and/or the head is warped or
> cracked. A compression check is certainly in order but he will have to buy
> a compression tester.. I'm not sure if he wants to spend the money.

I'd skip the compression test and pull the head at this point, there's no 
sense in wasting time and money on the compression test when the head has 
to come off.

> My understanding of diesel heads is that there are such tight clearances
> that a warped head is not worth trying to resurface. If this is the case,
> what is the going rate for a diesel head? $50? $75?

Although the Bentley states that the head can not be resurfaced, you can
generally get away with knocking a bit off to restore a mildly warped
surface, especially if the head gasket used is a 1 or 2 hole/notch gasket.  
The reduced head height can be accounted for by going up to the next
thickest head gasket - if you already had a 3 hole/notch gasket, then
you're already there, but you can go a bit further.  Talk to a machine
shop with experience in VW diesels.  Going rate for a diesel head depends 
on condition and availablity.  I would not install a junkyard head without 
having it inspected for cracks/warpage, and then after that, rebuilt (new 
guides, vlaves refaced/replaced etc.  A rebuilt head would probably run 
$250 or better.

> One last thing-- for those who have done a headgasket on a vw diesel, how
> difficult was it.. and did you need any special tools to work with the
> injection pump being driven off the timing belt, etc?

I've done a few... :)  There are special tools required - a locking plate 
to lock the cam precisely at TDC and a locking pin to lock the injector 
pump at TDC as well.  With some luck you may be able to find a deep socket 
whose OD is close enough (tighter, not looser) than the factory tool.  
I've ground just a wee bit off a 7/16 deep well 3/8 drive and used it 
before with good results.  If pump timing is suspect, or the pump was not 
locked and the belt installed perfectly, it will be necessary to time the 
pump afterwards, which requires a dial indicator and special adapter.  A 
Bentley is a must, especially if you've never done it before.  I've seen 
all sorts of wild things done - from the cam being 180 degrees off when 
the belt was installed to starting the engine with the locking plate still 
in place (which breaks the slot at the end of the cam so the engine can't 
be reliably timed again.)

HTH,

Drew


> 
> -Toby
> 
> _______________________________________________
> Scirocco-l mailing list
> Scirocco-l@scirocco.org
> http://neubayern.net/mailman/listinfo/scirocco-l
> 

-- 
/=============================================\
|  84 Wolfsburg Edition TurboDiesel Scirocco  |
|    http://scirocco.cs.uoguelph.ca/gtd       |
\=============================================/