Really bad diesel engine noise

[expat2000]

Hi all


Started my car this morning and I am getting a really bad clattering noise from the engine. Car is a 98 A4 B5 1.9 TDI (AFN) with the 4 speed auto box (01N).



https://www.dropbox.com/s/x6rbb8bg1f13a9l/20151114_112038.mp4?dl=0

As you can hear from the video it only happens at tickover and reduces from about 1500rpm and disappears completely at 1800 rpm. When I was under the car it seems to be coming from the back of the engine near where it meets the auto box.


I cant find anything obviously loose in the engine bay but I'm not keen to drive the car until I know what the problem is.


Any suggestions as to what might be the problem. After listening to various you tube videos I was tending towards a DMF failure but I have also read that the auto box doesn't have a flywheel per se so not sure where to go now.


Cheers


Stuart

[Gazwould]

Exhaust manifold leak ?

[expat2000]

Would it make that much noise? Its really really loud.

Not sure if its related but i have had auto box problems in the past. Last year a leaking sump so changed the fluid and filter in the box at the same time. Earlier this year I had a radiator leak which leaked coolant into auto fluid (stupid design feature). Since then I have changed the radiator and flushed and refilled the transmission twice to try and get the last of the coolant out of it.

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[expat2000]

Update but no progress:

Yesterday evening I pulled the nose into service position and removed the auxiliary belt. Mainly to rule out any non engine parts causing the noise.....and the noise is still there. So I know for definite its not the AC, power steering, fan, alternator etc

I scanned my car with VCDS and gearbox came back clean, my cheap ebay lead crapped out though and I couldn't get a reading from the engine so may have to get another and re-scan. I think I may pick up some injector cleaner and run it through as cant think of anything else to try.

One thing I did notice is that I appear to have a coolant leak, the level in the header had dropped quite a bit since last check and its not the first time this has happened. Cannot see any obvious leakage and the oil is clean (no emulsification). May or may not be related but thought it worth a mention.

The most baffling thing is that when you rev the car, over 1750 rpm its as smooth and quiet as it has ever been, its very odd.

Any other suggestions?

[expat2000]

Following advice I filmed the flywheel/flexplate, does this look as bad as I think it does?

Dropbox - 20151122_140559.mp4 (https://www.dropbox.com/s/pxcjmcays6pb1ty/20151122_140559.mp4?dl=0)

Dropbox - 20151122_140636.mp4 (https://www.dropbox.com/s/aoy90ps1fir5mer/20151122_140636.mp4?dl=0)