Date: Sat, 18 Jul 1998 21:21:14 PDT
Reply-To: Sean Bartnik <bartnik@HOTMAIL.COM>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Sean Bartnik <bartnik@HOTMAIL.COM>
Subject: Low compression -- cause located
Content-Type: text/plain
Hey all,
Today I pulled the engine out of my '81 air-cooled Vanagon (nice having
a garage that the Westy fits in) to try to locate the cause of the low
compression in #1.
The plan was to replace that 1/2 head with a spare good head I had from
a spare engine.
When I finally got the head off I did not find any pounded out valve
seats, but I did find a nice big hairy crack between the valve seats in
number 1, and a similar crack forming in 2. There were also other
cracks in various locations.
So, once I got a load of that, I wanted to take off the 3/4 head and see
what was up. When I pulled that one I also found a few cracks and I
also found that the #3 exhaust valve seat appeared to be receding into
the head. Not cool. I still had decent compression but I figure that
won't last long if I keep using the head.
So I checked out the spare 3/4 head I have and it's not really any
better. It's got one crack in it. The valve seats look OK, but the
sealing surfaces in the combustion chambers (where the cylinder seats
into the head) look like someone went after them with a mini-jackhammer.
They are really chewed up. I imagine this was damage due to
pinging/detonation? There was a LOT of carbon buildup in the combustion
chambers of this spare head.
So now I'm in the market for rebuilt heads. I plan right now to go
through Bus Depot and get the AVP heads, which Ron has for $180 each.
I'll be checking out the archives to see what people have to say. I
think the only two places I would go are AVP or Mark Stephens, and
hopefully I can get them quickly from Ron.
While in there I also found some stuff that was contributing to my
overheating problem: Found a bunch of cruddy scunge clogging up some of
the fins on the cylinders, as well as some leaves and lots of large
paint flakes. Weird. Also found some dirty scunge on top of the oil
cooler, which was undoubtedly reducing its efficiency. Now I'm taking
the time to clean everything up well.
So I wound up replacing the rear main oil seal (fan end) and will
replace the oil cooler seals, and will re-replace the pushrod tube seals
(just did this not too long ago, but hey, I'm in there again...) and
basically clean things up so I'll have a leak-free cool running engine
again. BTW, it appears that I was leaking some oil from that rear main
seal, so now that's one less thing to leak.
I'll keep you all posted.
Sean Bartnik
Fairfax, Virginia
============================
'81 Vanagon L Westfalia
'74 Karmann Ghia convertible
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