[Vwdiesel] '96 Passat TDI engine noise nightmare!

[Mike Maguire]

This is a multi-part message in MIME format.
--
[ Picked text/plain from multipart/alternative ]
Hi,

I posted the note below over at vwpassat at yahoogroups.com in the middle of t=
he night (well about 5 am Sunday over here) and so far have got 3 suggestio=
ns. Posted the same to Fred's with 20 reads & no suggestions so far.

1=2E    Don't jump off that bridge!
2=2E    Could be the nut on the end of the crankshaft pulley has worked loo=
se, i.e. it's a driven pulley wheel that's loose ( & a very helpful suggest=
ion to not drive it any further & how to check & what will happen if the ke=
y breaks ... very nasty!).    3.    Bolt holding the clutch pressure plate =
to the flywheel come out, spinning in
the bell housing when the flywheel/starter ring catches it?

Anyone here got any other suggestions or confirmation of the two above?  ..=
. I accept suggestion 1 & 2's advice not to drive the vehicle any further w=
ithout reservation at this stage! Oh ... it's an Upsoluted Z1 engine & so f=
ar, no apparent change in good performance from the engine except perhaps a=
 small increase in exhaust "smoke" when accelerating with the engine not ye=
t warmed up.

Is there anywhere else I could/should post to?

Mike
Exeter, UK



*************************************
*************************************
At 104K miles, a week or so my tdi engine started to make the odd noise ...=
 an occasional "chink" that wasn't increased in frequency with engine speed=
. Kind of sounded like something non-rotational catching something that was=
 rotating. Over the next few days this noise came & went, but didn't sound =
too bad, and everything seemed to be working just fine. Saturday I went on =
a longish fast run and stopped at my daughter's on the way back for a cuppa=
 (tea that is) ... and as I drove in to her place ... oh hell, what a horri=
ble noise! Still sounding like something non-rotating etc., but now serious=
ly noisy and really quite frightening. Not so much "chink" as "rattle/crack=
/rattle"!!! and loud enough to attract notice from folks on the pavement!

Well, I've taken off the top cover over the cambelt and as far as I can tel=
l, although 44K miles on from the belt change, this seems fine (I can just =
turn the little pulley (?) which is bolted to the backplate at the top with=
 my fingers (so not too tight & not too slack I guess) and the belt itself =
seems ok.) The serpentine belt & v belt also seem fine although the v belt =
could do with just a little tightening (no slip or screech mind you)

So what the heck can this be? It's not cyclical, but clearly something is c=
atching on/crashing against something that is, although the frequency doesn=
't increase as the engine revs increase.

My thoughts ... it sounds perhaps like:

- a pully wheel driven by one of the belts that's loose in it's keyway and =
is driving some sort of freewheeling device - maybe the water pump impeller?

- a starter dog that's catching on the starter ring gear teeth?

- something very very nasty in the fuel pump?

- something that's come loose in the engine itself which is catching on som=
ething rotating ... but intermittently?

- something very very nasty in the aircon compressor? (my aircon went o/s r=
ecently ... loss of refrigerant & then again after replacement by the deale=
r ... and subsequently, when I depressed the aircon switch, the usual disti=
nctive metallic "click" that indicates the pump has cut in also disappeared=
 =2E.. could this be the signs of an aircon pump beginning to take itself a=
part internally?

Whatever it is folks, this is a very nasty, loud & distinctive set of noise=
s and I am terrified of the likely costs in getting anyone to munch their w=
ay through replacing this and that component and destroying my wallet in th=
e process. Anyone else experienced anything like this?  Any suggestions apa=
rt from jumping off the nearest high bridge?

Mike
Exeter, UK

'96 Passat TDI Estate
*********************************
*********************************

--