Date: Thu, 13 Sep 2007 20:26:17 +0000
Reply-To: rubatoguy@COMCAST.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Todd Last <rubatoguy@COMCAST.NET>
Subject: Re: How do you check compression?
Does it matter if the throttle is held wide open or left closed?
I recall some instructions which stated to have the throttle held open when checking compression.
Opinions?
Todd
'88 Westy
-------------- Original message ----------------------
From: "Mike "Rocket J Squirrel" Elliott" <camping.elliott@GMAIL.COM>
> Standardized measurements? What a concept!
>
> Yesterday I did a slap-dash quickie to see if one of the cylinders was
> significantly different from the others. Made rough note of numbers.
> Posted information and that triggered a series of questions which is
> making me go back and look again. There is a Bentley's way of doing it
> (thanks Mark) but there might also be a rule of thumb way of doing it
> and since everyone is looking over my shoulder to judge what I am
> seeing, if they use some rule of thumb method which is different from
> the manual, I wanted to know about it.
>
> Measurements per Bentley's after lunch, Pacific time.
> --
>
> 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 9/13/2007 11:17 AM 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
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> __________________________________________________________________________
> >>>>
> >>>> __________
> >>>> Luggage? GPS? Comic books?
> >>>> Check out fitting gifts for grads at Yahoo! Search
> >>>> http://search.yahoo.com/search?fr=oni_on_mail&p=graduation+gifts&cs=bz
> >>>>
> >>>
> >>
> >>
> >>
> >>
> >>
> ________________________________________________________________________________
> ____
> >>
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> >>
> >
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