Date:         Tue, 11 Dec 2001 06:48:19 -0800
Reply-To:     Michael Ramer <elvisramer@HOME.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Michael Ramer <elvisramer@HOME.COM>
Subject:      Leaking thermostat housing/head reseal followup
Content-Type: text/plain; charset="iso-8859-1"

    After replacing both head gaskets, coolant pump, and finally the
thermostat and o-ring, I discovered a nagging leak around the housing.
    Twice I removed and cleaned the inner sealing area where the thermostat
resides and twice I experienced a leak after reasssembling. I tightened it
down as evenly as possible without breaking the brittle plastic, which is
not easy, given it's location. Obviously it was leaking from under the
thermostat where there was no seal.
    I began entertaining the idea of adding another o-ring under
the [OEM] thermostat to assist in sealing. The Bentley does not indicate
such, as I
found only one [on top of the thermostat] when I replaced it.
    I had a leftover gasket set from an engine build, and found three
o-rings of different thicknesses which might work: 1.90mm, 2.85mm and
3.40mm- the latter being the same as the o-ring supplied with my thermostat.
    I placed the smallest one (1.8mm) under the thermostat and reassembled
using the larger, original 3.40mm on top. This seemed to be the best fit the
others would not allow the upper housing to mate properly to the lower 1/2 .
    Well there you are. No more leaks. Anyone else experience this problem?
It appears that
the tolerances in the housing are a little on the wide side? Perhaps it
would have sealed after heating up? I don't know, but after all the work I
put into this engine, I was not about to deal with any more leaks.
    Yes, it was indeed a messy job to reseal the heads, especially with the
engine still in the van. In hindsight, I'd consider removing the engine for
this repair.
    I used JB weld to repair the corrosion to the heads, which should be
good for as long as this 116k mile engine has life left in it.
    In addition to the repairs needed, I also match ported the intake
runners to the head (they were about 1~2mm smaller ID), and opened the
exhaust ports on the heads to match them with the exhaust header in hopes of
improving bottom end power. No real noticable difference in performance
other than knowing it's done and I can continue on with other mods if
desired.

Mikey 87 Westy