[Vwdiesel] Oil in coolant, headgasket etc....

[rod welch]

Hi there... it's snowing .... but had a couple of clear days to get on with
something on the van...

First off... Testing the oil filter cooler/heater... Had the engine running
for about an hour in all with the hose bypass, didn't see any oil coming
from any where, (so I guess it's OK) took it off in the end. Is it worth
pressure testing the water passages anyway?
The temp. guage and warning light max out 'cos there's no coolant in the
tank...
Flushed the system out with a litre of alchol and quarter of a bottle of
floor cleaner. There was loads of black crap in there... it feels like
grease, kinda sticky not "oily", really difficult to get off your hands. No
smell. 

Put a clear section in the 1" hose that runs back to the expansion tank.
(branches off the head to rad?? hose that split) At idle I don't get any air
bubbles.  Accelerating gradually there are no bubbles until I drop the revs
off, then there is a bust of "foamy" bubbles.  Same happens if I blip the
throttle, bubbles come on the release. With the cap off, and my hand on, the
expansion tank, there is loads of "suck" during acceleration and higher
revs.

Put a pressure guage on the headport (see, I'm learning...) and with revs it
goes up to 7bar, (oh yeah... there was about 4litres of oil in there).....
It settles at about 1.5bar at idle during the first 15 mins and then slowly
starts to drop (at idle) until it's warmed up ('bout 30-40 minutes), then it
seems to sit at zero... 
If I rev it, when guage drops back down to about 0.5bar, it hangs there for
a second and then suddenly flips to zero... Could it be the guage isn't
sensitive enough at lower pressures? It was the cheapest I could find
(35euro's)... 

So what do you think?  Headgasket? 

Would a leak down test? have to be done to make sure or what? (and what's
one of them in Finnish??  Talking of Finnish... say this..
Maaseutuyrittäjäntuotantoresurssienkehittämiskoulutushanke...)

Ps. No blowby or other unusual sights or noises...

Thanks...
Rod
Finland