[Vwdiesel] 02 TDI, faint tapping when under load

[Tad]

Maybe an injector problem?  Bad pattern causing a louder-than-usual diesel
knock under certain conditions?

I wouldn't expect to be able to hear the EGR/turbo vacuum modulators from
inside the moving

Have you tried reproducing the sound at a standstill by powerbreaking the
automatic?  Just a thought...

And speaking of the automatic... could it be a tranny noise?  That would
explain it being not-perfectly-synced with the RPM.

On Mon, Dec 19, 2011 at 11:47 AM, Stephen Sherman <spsherm at msn.com> wrote:

> Thanks for the replies.
>
> Answers to questions (and ask a few of my own)
>
> There are 109K miles on the engine.  Seems to be very well maintained. PO
> did regular oil changes and the like.
>
> Possibly valve lifters (though of that), but when I probed around the
> valve cover with the stethoscope, didn't hear anything that sounded like a
> tapping.  And I would assume that a lifter would be noisy at all rpms and
> especially low rpms, with and without load. Doesn't explain the tapping
> going away when you lift the foot of the go pedal at high rpm (2k or so).
>
> I can't say for sure if the tapping frequency is in sync with engine rpms.
>  It wasn't conclusive to me (but then again I have lousy musical pitch
> too). It does seem to vary some with RPM or load, but not entirely in sync.
>  If it was part of the engine mechanics it should be exactly in sync with
> the rpms I would think.  It might be, but I wouldn't swear to it.
>
> Either the ERG or Turbo control valves sound like a good thing to check
> out. I suspect the Turbo one, as it comes on with engine load and IIRC the
> ERG is not really doing much at load. Might explain both the load
> connection and the mystery location (engine vs dash) since that valve is
> right on the firewall.  Now just have to figure out how to check it.
>
>
>
>
>
>
> ______________________________**_________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/**mailman/listinfo/vwdiesel<http://www.audifans.com/mailman/listinfo/vwdiesel>
>