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

[Mark Shepherd]

Hi chaps,
Thanks for all the constructive comments. 
Sorry for my slow response, but I have been deciding my next route. This item arrived today:

http://www.ebay.co.uk/itm/251065476060?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
All I’ve tested so far is my apparently abrasive finger tips, and the toilet cistern. The basic headphones work , but I’m trying to repair a proper pair of 
DJay’s type head phone to exclude the noise better on the engine.

The uploaded video of my cam [see below] is a few seconds into initial start-up. I was hoping to be able to see the cam sync’d with the audio. I don’t have 
any software that will directly display both.
[Confession the previous link was not of an oscilloscope /spectrum analyser, although I may have an old one somewhere, but it was video of the audio trace 
as displayed by an old but good Nero 7 package with NeroWaveEditor :oD]

My old camera does 30 fps, and the camera conveniently started at #1 TDC, and the engine was rotating at 840rpm, so cam at 420rpm, or 7 rev per 
second. Thus very close to 4 frames per cam revolution , so in slow motion, 1 3 4 2 cam order can be observed. 
My goal is to find the offending cylinder so that I can check to see what mechanically differs from the other 3 when I take the sump off...
I should drop a different set of injectors in; to definitely eliminate them as a cause, but I tend to find the injectors need a few miles to reach optimum 
operation.

http://s1329.photobucket.com/user/Quantum-man/media/IMGP2506_zps61449767.mp4.html


Using my camera in audio mode I was able to rerecord the sound track, and align it with the Nero. The video can be slow-mo’d with my Quicktime package 
linked to my ACDsee photo viewer. Having been so clever, I’m still struggling.
Firstly because the background noise echoes etc increase when engine running with the cam lid off, and secondly because Quicktime decided to upgrade 
itself beyond the scope of the version of ACDsee that I use , and then have the cheek to make most of the manipulation buttons only available with the 
‘premium’ version.:o(

Valve shim gaps on this ‘new’ mech head are all set to 8 thou, except #1 inlet is 5 thou, and #3 inlet is 6 thou. Quite tight, but I’ve run tighter, and maybe 
more power?
I carried the injectors over from the old head. Initially the timing returned to the seemingly low 0.57mm, but injectors have been kept around 130bar. They 
were originally 155 bar but I had changed springs and shims around with some135 bar Ford ones. 

Since head change starting had still been good, but was smoking on startup, running lumpy etc for a while, first thing in the morning, but clearing up after a 
few 100 yards, and not returning all day. Thinking a lazy injector, I stripped them out and tested, one would seem a bit poor on atomisation so stripped 
down, and sorted for a few weeks, then it would return. On the last ‘rebuild I decided to match them better than the 127, 130,130, and 132 bar. Got them to 
131, 130, 130,130. 

Advanced the pump a little in an effort to help the vibration issue [I’ve had since rebuilding the oil pump and ‘moving’ the engine mountings to get the sump 
off]. Prior to doing that I had been running at 750rpm, after that I had to increase idling to about 840rpm. I digress. 

OK still smoking at startup, from one injector.. Then it struck me, this was not my old head, and this one came with water filled injectors and it’s own 
glowplugs... Checking using a thermocouple and 10 second glow soon revealed #3 plug dead.. Why didn’t I check that when installing or upon noticing the 
smoke issue ? One off the old head soon cured that and the vibration at idle also seems to be improving. 

Still I have this knocking , which is what this thread was all about. At the time of the re-ring, none of the wrist pins had any play in them, and only one piston 
had a rubbed skirt, and I put that down to the worn out and stuck in rings remember 7 out of 12 were stuck! That was all about 60 to 70 000 miles ago!
Engine had done high miles so I assumed the bearings weren’t going to change with my light use. 

I had a quick go with the rod stethoscope touching all the injectors, bosses, and along the valve cover, then on the turbo ex/in manifolds, the alt and the 
water pump, and the injector lines at the pump. Many different noises and grunts. 

Might try ear plug headphones and my very good ear muffs for circular sawing. I guess I could rig up a recorder sometime. 
Annoyingly, despite the knocking, Last fill up 55mpg[imp] mostly town....

========================================
Message Received: Aug 31 2013, 07:51 PM
From: "Mark Shepherd" 
To: vwdiesel at vwfans.com
Cc: 
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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