Fast paced rattle coming from 300tdi

Anymore thoughts?

I'm thinking of replacing vac pump unit as I think the noise is coming from there.

Thanks

have you stethescoped it yet?

I know of one failure method where the vac pump will make that noise but usually there is an assosciated loss of brake boost with it..

Im thinking its a harmonic of something thats worked loose...

the bolts that mount the IP support brace could make a similar noise...

Check the injector clamping stud nuts, i had a lose one and it made a hell of a racket til i tightened it.

Our old '97 Tdi had a clatter in the engine, (over and above the normal din), it was the tappet plunger for the Wabco vacuum pump, had a deep groove worn in it where it runs on the cam, there is an oil spray somewhere there that was clogged and had caused the surfaces to wear, normally there should be a rotation of the tappet surface to even out the wear, (or so the theory goes).
This wear can also reduce the pump stroke and effect the pump's performance.

I had a question on a similar noise a few months back.
Turned out to be both the Vac Pump and the fuel lift pump were U/S.

I've checked injector clamping studs, theyre al good but can see one is weeping slightly (next to fix)
I have put a screwdriver to the ear and its coming from Vac Pump.

Brakes still ok. Will grab a new one and pull the old one off for a looksi.

Cheers,
Rez

Quote:

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Originally Posted by Rezley

I've checked injector clamping studs, theyre al good but can see one is weeping slightly (next to fix)
Rez

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While you are getting the new vac pump, order (or make) some new injector clamping studs. The standard ones stretch and can only be torqued a couple of times before snapping.

It is covered elsewhere, but just a reminder that when installing a new vacuum pump double the gasket thickness ( use 2 gaskets)

In follow up to this thread.
I purchased a new Vac Pump.
On removal of the old pump it was obvious the little grub screws that hold the main plunger shaft in were about to fall out allowing the main body of plunger to float in the housing.

I have pics compared with new item if anyone is interested.

Test drove today and no more fast paced rattle.

Thank you to all those whom helped.