Carbon and compression tests

["Bernard Littau" <bernardl@acumenassociates.com>]

Hi all,

I did a pre-purchase compression test on a 5k turbo motor in an '86 Audi I
am considering purchasing.  The car was luke warm, and we got 130 128 120 60
80 on a dry test.  This was deemed not good.  A wet test brought number 5 up
15 to 95.

Owner took same 5k to his mechanic, and they did a warm compression test
getting 155, 150, 150, 145, 150.  Cold was in the 110-125 range (I didn't
get the actual numbers).

Owners mechanic commented the only logical explanation is that when my
mechanic
did the test, carbon flakes probably got into the space between the valves
and the valve seats.  When ever you take the plugs out it is likely that
some of the carbon buildup flakes off into the cylinder.

Has anyone run into this sort of thing?  Plugs did not look carbonized.
They even looked a bit on the lean side.

Comments in general on compression tests on the I5?

Best,

Bernard Littau
Woodinville, WA
Audi-less