Date: Tue, 19 Jun 2007 08:17:00 -0700
Reply-To: David Kao <dtkao0205@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Kao <dtkao0205@YAHOO.COM>
Subject: Re: Is this the cause of my engine compression problem?
Content-Type: text/plain; charset=iso-8859-1
It's too early to jump on the conclusion. I will have to drop the engine
and take it apart to find out what's really wrong.
I already did the oil trick. The compression did read higher after squirting
some oil into the spark plug hole. But the oil reduced the volume of the
combustion chamber which could contribute to higher compression reading as well.
I have only 4 days, including today, before my planned camping trip in Yosemite.
I am trying to decide to tear down the engine before or after the trip. I can't
drop an engine in 15 minutes like you do. It's more like 3 hours for me. 4 days
is a little rush. I probably should do it after the trip to do everything right.
I don't think I will need a new gasket set. I still have one tube of gasket sealant.
Everything else can be reused still.
I am leaning toward doing it after the trip. I will have to be careful to not push
the camper too hard. I will check the compression after returning from the trip.
It will tell if it is a break-in issue.
Benny, thanks for taking the time to feed your experience to this list. I am sure
some listees are going to benefit from this thread in the future. I don't mind to
stumble on this rebuild. I am determined to get it done right.
Cheers,
David
--- Benny boy <huotb@VIDEOTRON.CA> wrote:
> David, now i feel bad because i told you NOT to check the rings...
>
> Let's try another compresion test, remove rocker on that side to be sure
> valve are fully close, pour a few spoons of oil (20W50) in that cylindre,
> try another compression test. If compression is higher, it must be the
> rings. It's NOT the piston pin circlip that came out and scratch the wall,
> believe me, compression would be way lower than 90, i know :-)
>
> Many have use COFAP and with great Success, BUT, sometime, they do have low
> compression at first, pistons and rings can take more than 2000 miles before
> they seat properly.
>
> Ben
>
> On Sat, 16 Jun 2007 16:49:23 -0700, David Kao <dtkao0205@YAHOO.COM> wrote:
>
> >This is to keep everyone posted. I found the real problem eventually by doing
> >a pressure test to the engine.
> >
> >I borrowed a compressor and coverted my compression tester into an adapter for
> >pressure testing the engine. Found excessive leak in my #1 cylinder through the
> >piston rings into the crank case. I could feel a strong flow or air coming out
> >of the blowby breather hose, which has an opening inside the S shaped intake
> >rubber bellow. I could feel a strong flow of air flowing from the crank case
> >through the hose into the bellow. It pushed my finger out when I tried to block
> >it off.
> >
> >Ouch..... It's a new liner there!!! How will it leak like that? When I did the
> >same to cylinder #2 the pressure was only at 20 PSI and it pushed down the
> piston
> >and caught me by surprise. It could not push the #1 piston even at 50 PSI.
> I had
> >transmission in 1st gear and parking brake on with wooden blocks in front
> of the
> >front wheels. So the van did not try to run away but the tail of the van sank a
> >few inches. There was no obvious air flow through the blowby breather hose when
> >testing cylinder #2.
> >
> >Repeated the pressure test 4 -5 times and the results were consistant.
> >
> >The leak is less severe for cylinder #3. But the air flow is obvious there. I
> >think these are enough to conclude that I have leaking rings on #1 and #3
> cylinders.
> >The leak was so bad it actually caused slight over heating during my
> weekend trip
> >of 320 miles.
> >
> >The liner is new, with 800 break-in miles. I have to conclude that Cofap is
> junk.
> >Or at least the set I got is near junk. Further breaking-in probably won't make
> >any improvement as I have had 800 mile on it.
> >
> >My patience is running out for now. I won't try to fix it for the next week
> or two.
> >I don't think I did anything wrong in istalling the liner. I did not align
> the rings.
> >According to Benny this is not likely a problem. I have heard that Cofap
> has a wide
> >range of quality distribution between junk and excellent. Can anyone
> confirm this?
> >
> >David
> >
> >
> >
> >
> >
> >
> >
> >
> >
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