David-

I am not an expert on the I4, but know the flat motors very well, and can
give you insight from those. You didn't say how many miles are on the
motor, so it is tough to say with much certainty.

The variance is probably manufacturing variance. A teeny-tiny difference in
the length of one of the connecting rods, or crank throws can push the
compression much higher on one cylinder. The #3 in the I4 may be better
lubricated and cooled than the others. Our 1985 TD is not hydraulic; if
this gas is not hydraulic, the valves may need adjusting, thus the skewed
#'s. That's a cheap service, and lends tremendous results.

In any case, your #'s look good. I wouldn't worry too much.

Cheers,

G. Matthew Bulley
Bulley-Hewlett & Associates
www.bulley-hewlett.com
Cary, NC USA
888.468.4880 tollfree

-----Original Message-----
From:   David Marshall [SMTP:vanagon@VOLKSWAGEN.ORG]
Sent:   Saturday, August 14, 1999 1:00 AM
To:     vanagon@GERRY.VANAGON.COM
Subject:        Re: Fwd: Jetta engine question

Tonight I decided to check my compression on the 1985 Jetta Carat engine
installed in my 1984 Westfalia.  The engine was warm prior to the test and
all spark plugs looked fine (slight brown) as they are 5000km old Bosch
Platinums.  All plugs were removed and the throttle held wide open.  The
engine was run for five "ka-thups" and the gauge was read.  The
measurements were:

#1 - 170
#2 - 170
#3 - 190
#4 - 170

According to the Bentley Manual 145-189 PSI is what these engines should
rear with the maximum difference of 44 PSI.  I realize that I am not close
to the 44 PSI difference limit, but why would one cylinder be way higher
than the other three?

--   David Marshall -                    - Quesnel, BC, Canada   --
--    78 VW Rabbit, 80 VW Caddy, 84 VW Westie, 85 VW Cabriolet   --
--       87 Audi 5000 Quattro, 88 2.0L VW Syncro Double Cab      --
-- David's Volkswagen Home Page        http://www.volkswagen.org --
-- Fast Forward Autobahn Sport Tuning  http://www.fastforward.ca --
-- david@volkswagen.org (pmail) or vanagon@volkswagen.org (list) --