Date: Thu, 13 Sep 2007 20:41:55 -0500
Reply-To: Max Wellhouse <maxjoyce@IPA.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Max Wellhouse <maxjoyce@IPA.NET>
Subject: Re: How do you check compression?
In-Reply-To: <46E97ED4.204@earthlink.net>
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I've always counted the wuh wuh's until the needle maxed out and
then gave the other 3 cylinders the same number of wuh wuhs. Seemed
fair to me, but engine compression is NEVER fair.
DM&FS
At 01:17 PM 9/13/2007, Mark Drillock wrote:
>Why not read and follow the MANUAL?!!! Then we can compare over time
>with meaningful results.
>
>The VW service manual says warm engine, all plugs out, disable coil,
>crank until gauge stops increasing, then read gauge.
>
>Bentley 15.20
>
>Mark
>
>
>David Kao wrote:
>>It sounds like chuck, chuck, chuck. The needle of the gauge
>>will jump (upward) upon each chuck (stroke). The question
>>is should it be measured until the needle stops moving higher
>>or should the reading be taken at the 4th stroke.
>>
>>Dennis suggested to take the reading at the 4th or 5th. But he also
>>said to read it until it reaches the highest reading.
>>
>>I believe a cylinder with excellent compression will give you highest
>>reading on the 4th stroke. A cylinder not in optimal compression
>>will require 6 - 8 strokes to reach max. reading. So the reading as
>>well as number of stroke should both be considered for judging the
>>compression of a cylinder.
>>
>>Vanagon engine seems need more than 4-5 strokes to reach max compression
>>reading. Correct me if I am wrong about this.
>>
>>David
>>
>>
>>
>>
>>--- Michael Elliott <camping.elliott@GMAIL.COM> wrote:
>>
>>
>>>Engine warmed-up, cold, doesn't matter?
>>>
>>>Counting number of strokes -- is that the number of wuh-wuh-wuh sounds the
>>>starter makes?
>>>
>>>--
>>>Mike "Rocket J Squirrel" Elliott
>>>71 Type 2: the Wonderbus
>>>84 Westfalia: Mellow Yellow ("The Electrical Banana")
>>>74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>>>KG6RCR
>>>
>>>
>>>
>>>On 9/12/2007 8:29 PM Dennis Haynes wrote:
>>>
>>>
>>>>Some more variables. Crank until gauge stops rising. You can hear the
>>>>change. Count the number of strokes. Should be 4-5. The design of the
>>>>gauge can affect this. The hose length and placement of the valve will
>>>>make a difference. Of course you will also want to do a leak down test. On
>>>>older engines it is common for the front two cylinders (1-3), to show
>>>>lower compression then the rear and still check good with the leak down.
>>>>This can indicate worn cam lobes.
>>>>
>>>>Dennis
>>>>
>>>>-----Original Message-----
>>>>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>>>>David Kao
>>>>Sent: Wednesday, September 12, 2007 10:31 PM
>>>>To: vanagon@GERRY.VANAGON.COM
>>>>Subject: How do you check compression?
>>>>
>>>>I was told by a mechanic that when checking compression for a 4 cylinder
>>>>engine I should get 4 strokes, no more than that, and get the reading.
>>>>But Bentley Manual says to continue to crank until getting the highest
>>>>reading. So how do you folks do it? How many strokes on the average do
>>>>you crank to get the highest reading?
>>>>
>>>>David
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>__________________________________________________________________________
>>>>__________
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>>
>>
>>
>>
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