[Vwdiesel] low compression

[LBaird119 at aol.com]

In a message dated 8/11/2010 10:40:22 AM Pacific Daylight Time, 
cfgeiser at gmail.com writes:

> First; diagnostic thoughts (broken ring(s) on 3?  broken valve? or just
> tired worn engine?). Anything valve-wise that can be checked by pulling 
> the
> valve cover other than basic adjustment?

  First thing I'd check is valve adjustment.  Unless it's hydraulic 
valves but I suppose you could have a flat one that's not pumping 
up, thus not opening the valve enough (vs not closing the valve 
from being to tight of clearance).
  Could be a broken ring but the oil shoulda brought it up more than 
that, likewise with a bad injector.  The oil test would most likely 
bring up the compression more than that.
  Blown head gasket would usually blow into #2 but it's good so...

> 
> Secondly - what do you think is the natural course of this engine from 
> here
> if I keep driving it - will it at somepoint lose enough compression that 
> it
> won't start, or do you think there's a good chance that #3 will
> catastrophically fail and send a rod through the block?

  Oh, eventually it'll lose enough compression it won't start but that's 
usually worn out rings and the bore tends to go with it, since there's 
not much leeway there.  Not going to throw a rod through the block 
unless the rod bearing or nuts go.  It'll start knocking before it goes.
Could score the cylinder walls but it'll likely need bored (technically) 
anyway, once you get into it.  Broken ring should wander around in 
there without doing damage so long as you don't go rapping it out 
a bunch.

> 
> I'd ideally like to use it for about 1000 miles yet this summer, then pull
> the head and have a look over winter, but I'd rather not lose the block in
> the process.
> 
> 
  Odds are you can but yeah, leaking/non opening valve or a broken 
ring is most likely it sounds like, since you have no bubbles into the 
coolant.
   Loren