[Vwdiesel] 5+ years of engine noise 1.6TD mech head

[James Hansen]

To me, it sounds like a valve with too much lash.  Bottom end stuff, being
heavier, is much more clunky and lower frequency, not a tapping sound like
this is.
It's not valves versus piston, hard to describe in words, but it's less tick
tick, more clucky sounding then as the piston moves away, the sound changes.
Instead of an oscilloscope, try, a stethoscope with a long probe, and poke
around for the loud area.  Noise on deceleration would be pistons if this
were a gas engine with high vacuum  on deceleration, but that isn't the case
here. Any vibration that accompanies it? You've swapped injectors and have
the injector line anti-vibration supports installed I assume?
-james

-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com] On
Behalf Of Mark Shepherd
Sent: August-31-13 12:51 PM
To: vwdiesel at vwfans.com
Subject: [Vwdiesel] 5+ years of engine noise 1.6TD mech head

Hi chaps,
In an effort to cure my engine noise, I have decided to share a video of the
sound of my engine!

http://s1329.photobucket.com/user/Quantum-man/media/IMGP2505_zps4a50dfac.mp4
.html

As some may be aware this engine suffered from an overzealous head skim, and
has always knocked since. Various experts have suggested big ends, little
ends, injectors and tappets Turned out to be valve clash...[No discernible
wear to shell bearings back in 2009] No problem, because I stupidly broke
the cam and cam belt with a finger tight tensioner, this summer. :o( 

Great, a genuine VW CX complete and unskimmed head was found and installed.

That should have cured my noise issue, however it hasn't. Just maybe I do
have a bearing issue now due to the thump of the pistons hitting the valves
on the old head and hammering the cam lobes enough to break the cam in 2
places.
Currently the knocking still happens like previously when decelerating with
engine switched off but in gear, but now there does seem to be a change in
sound when applying loading.The sound track clearly shows problem confined
to one cylinder only and only on compression stroke. Previously the sound
track had shown a secondary noise from another cylinder. I will see if I can
confirm this from an old recording if I can find it. 
Most of the young mechanics I come across don't have experience with the
expected noise levels of this type of engine...
Cheers,
Mark



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