[Vwdiesel] Coolant leak

[Andrew .Libby]

Because of the various channels in the head gasket, there are a variety of
ways that a head gasket can fail and the various ways usually do not occur
simultaneously.  If the head gasket has failed so that coolant leaks to the
erxterior of the engine, that would have absolutely nothing to do with
pressurizing the coolant with combustion gases or oil mixing with the
coolant or oil leaking from the pressurized oil channel of the head gasket,
etc...  The lack of those other symptoms tells nothing about whether or not
the head gasket is leaking coolant to the exterior of the engine.
Similarly, if the head gasket was leaking to the exterior of the engine it
would not give any functional symptoms other than the symptoms from a leak
at the flange, e.g visible coolant and a drop in quantity in the expansion
tank.  While it is good that you have not overheated, the information that
you haven't doesn't help to determine whether the leak is from the head
gasket or coolant flange.

Regardless of any of that, if there is any question about whether or not
the coolant flange is the source of the leak, then address that first.  Not
only is it a more likely source of coolant leakage IMO, but also it is
easier and less expensive to address.  Good practices always address the
easiest and least expensive potential cause of the issue before moving on
to the next easiest and least expensive potential cause.


On Fri, Nov 16, 2012 at 12:12 PM, Bud <budski at gmail.com> wrote:

> Started getting a coolant leak about a month ago (1k miles).  Couldn't tell
> where it was leaking until this morning when I started it up cold.
>
> On the back of my 85 1.6L Golf head (drivers side), there's an inconsistent
> leak.  But I'm not sure if it's the head itself or the coolant flange that
> ties into the heater core in the passenger compartment that's weeping.
>
> I opened the expansion tank and fitted a nitrile glove over the opening and
> sealed it with a rubber band.  The glove did not inflate it actually was
> sucking into the tank a bit.  There is no coolant in the oil that I can
> tell and when I rev the engine I just get the normal black smoke or the
> grayish smoke of unburnt fuel at startup.  No white clouds.
>
> I'm kind of leaning towards a bad seal on the coolant flange weeping along
> the head joint.  After a minute the weeping stops and the coolant has dried
> up.
>
> There's 165k miles on the rebuilt head and stretch bolts I have in there
> since my limited rebuild.  I have no overheating other than twice my gauge
> went erratic and then I saw the coolant was real low in the expansion tank,
> but still enough to cover the head and I just filled it up with water.
>
> Is there a life expectancy on the head gasket and stretch bolts?
>
> Thanks,
> Bud
> http://www.rhinocat.com/cvaf4u/
> _______________________________________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/mailman/listinfo/vwdiesel
>