[Vwdiesel] 1.6TD compression numbers

James Hansen jhsg at sasktel.net
Sun Dec 11 23:12:14 EST 2005

Today marked our last trip in the Westy this year, so I pulled the injectors
as soon as
I got home and did a hot compression test. The numbers were as I expected,
low at 390 - 375 - 330 - 330.
It's possible the weak battery resulted in decreasing values as I went
along, as the
cranking speed was getting slower. Pulses on the gauge went something like
150-200-250-300, which explains why it takes several seconds to start when
the GPs
don't come on - it takes several full revolutions just to get 300psi.

Don't worry about getting to 300psi over many revolutions... that's because
the volume of the precup is larger than it usually is because you have a
hose and and gauge connected to it.  They don't build up pressure to start,
they see the same pressure every time, and you are measuring that when you
crank the starter putting a little wind into the hose of the compression
tester each revolution, until it matches the compression that the precup
usually sees.

I would however be some concerned at the difference between the cylinders.
They should all break in relatively the same at the same rate. Yours haven't
and that sucks.
If it was me, I would do another compression test so you can monkey with the
engine this winter, or plan on doing another test in spring.
I know it's in a vanagon, and gets driven hard just sauntering around, but
did you drive the bag off it at the start?
Worst case,you may have to re-ring and re-hone.
How is oil usage and crankcase blowby?

Good you had a nice day.
It rained here today and yesterday and was +2 to +3.

No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.371 / Virus Database: 267.13.13/197 - Release Date: 12/9/2005

More information about the Vwdiesel mailing list