Date: Tue, 27 Dec 2011 01:33:56 -0500
Reply-To: John Lauterbach <jhlauterbach@BELLSOUTH.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Lauterbach <jhlauterbach@BELLSOUTH.NET>
Subject: Re: Compression test results for '84 Vanagon 1.9L with rebuilt
right head
In-Reply-To: <BAY152-ds21FE385E328C5DBE29B95A0AE0@phx.gbl>
Content-Type: text/plain; charset="UTF-8"
Hello Dennis,
Compression test was run as close to Bentley as practical. My Son was
up front with the key and his foot all the way down on the accelerator
pedal. We started with the engine at operating temperature, and there
is Mobil 1 15W-50 in the crankcase.
After we had everything back together and got our daily bicycle ride in,
we took the van out to run an errand. For some reason, it would not
fast idle, but after a few minutes, it ran quite nicely with none of the
problems of past two weeks. Weather has been cool and very damp so
there may a some other gremlins at work.
BTW, ever since your visit, my Son has been more than willing to get his
hands dirty and can't wait to help work on the van. Thank you.
John
On Mon, 2011-12-26 at 15:52 -0500, Dennis Haynes wrote:
> One problem with compression testing is that there are too many variables. The gauge calibration, check valves, hose length, etc. are variables. On the engine temperature, oil viscosity, and most important cranking speed have major effects on the readings. It is also helpful for the throttle to be held open so that the engine can pull in as much air as possible.
>
> Your readings are on the low side which could indicate low cranking speed and/or closed throttle. 120-150 is more of a normal range for these engines.
>
> I would be concerned with the fouled spark plugs, especially if more fouled on one side. Are they oil (wet) or dry (soot) fouled? Wet plugs are a sign of miss firing or excessive oil getting into the cylinders. The most common means for excessive oil is the intake valve guides. There should be valve stem seals on the intakes. Many shops leave these off and they often break and fall off.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of John Lauterbach
> Sent: Monday, December 26, 2011 1:41 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Compression test results for '84 Vanagon 1.9L with rebuilt right head
>
> Here are the numbers:
>
> First round:
>
> #1, 105, #2, 95, #3, 120, #4, 115
>
> Retest on right head:
>
> #1, 90, 90 #2, 120, 120
>
> Engine is a Boston Engine rebuild installed September 2003. Has about 45K kilometers on it.
>
> Plugs from left head were more fouled than plus from right head.
>
> After lunch, planning to retest with a squirt of oil in each cylinder,
>
> John
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