Date: Thu, 2 May 2002 20:15:26 -0400
Reply-To: "G. Matthew Bulley" <gmbulley@BULLEY-HEWLETT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "G. Matthew Bulley" <gmbulley@BULLEY-HEWLETT.COM>
Organization: Bulley-Hewlett
Subject: Re: Oil Leaks and Leak Down Test
In-Reply-To: <9F9D2D76D81DD311ADEB0090274F0562028D6083@calexchange.golder.com>
Content-Type: text/plain; charset="US-ASCII"
MT--
Those are decent results for an aircooled with 100k on it. If it weren't
for the oil leaks, I'd suggest you just drive it and quit worrying.
With the oil leaks in mind, both for the sake of your van and the sake
of the beautiful Canadian waterways into which your street run-off
accumulates, I'd suggest putting a rebuild in your near future.
Before you jump into buying new pistons and cylinders, though, take
yours to the machine shop and investigate their dimensions thoroughly.
There are oversized rings available, and on some of my few dozen Type 4
rebuilds I have been able to reuse the pistons and machined cylinders
with excellent results.
As for your thoughts about doing a "wet" compression test, don't waste
your time. Since the cylinders sit on edge, there is no way to assure
that each cylinder distributes the oil completely across the
circumference of the rings... you can end up with a 160 psi on one and a
110 on another without any real problems, just poorly distributed oil.
As warmer weather approaches, you may find your compression (100 psi) is
too low for easy starting after the motor warms up. It will be the coup
de grace for this motor's incarnation when you have to push-start your
van in the Zippy-mart parking lot.
Developing business and guiding change since 1996,
G. Matthew Bulley
Bulley-Hewlett
Corporate Communications
Business: www.bulley-hewlett.com
Alliance: www.ntara.com
Phone: +1.919.658.1278
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf
Of Thompson, Michael
Sent: Thursday, May 02, 2002 6:24 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Oil Leaks and Leak Down Test
Following helpful suggestions from the Vanagon community I took my leaky
aircooled Westy for a leak-down test. The reported test values are as
follows:
Cyl 1 100/30 psi
Cyl 2 100/62 psi
Cyl 3 100/44 psi
Cyl 4 100/50 psi
The garage says that the air could clearly be heard coming from the
crankcase breather. These strike me as very poor results indicating the
engine is in a very poor state and requires a full rebuild (as
recommended
by this garage - new pistons, rings and barrels as a minimum). Before
buying
the vehicle, I took it to a reputable VW specialist who said the engine
was
good. I have spoken with them regarding these new results and they
cannot
believe it and want to carry out their own leak-down test.
Now what I don't understand is the following:
1 The engine starts and runs well and has never failed me in 5
weeks
use (and that includes -15 degrees in Calgary).
2 The engine burns some oil but nothing exceptional for a 100,000
mile
engine. Slight blue smoke on acceleration.
3 I have monitored the air coming from the breather at idle and
higher
revs and it is not particularly blue or smokey.
4 I have oil leaking from the 2 main crank seals, oil cooler,
possibly
cylinder heads, and pretty much anywhere else it can find its way out
of.
5 If all this leakage was from blow-by, surely it would burn a lot
of
oil. Does a leak-down test positively identify the source of the leak?
If
the valves were not holding, could the air flow into the head and down
the
pushrod tubes into the case? Something does not add up here. I am
going to
carry out a normal compression test this evening and see if I can
increase
the results by putting engine oil in the spark plug holes.
I do not have a particular problem with power or the running, but the
oil
leak is too excessive on long or uphill/headwind journeys. Does anyone
have
any advice on my next move as at the moment it looks like an engine
strip
and rebuild!
As always, any help is much appreciated!
Regards
Michael
81 Westy 'Daisy'