Thread: 300tdi knocking noise

could it be a big end starting to fail

Take off the auxiliary drive belt and check the crank pulley for looseness. It may not be the keyway at fault, but the rubber insert between the pulley and the centre may have failed.

This has happened to a vehicle of ours recently.

Fix: replace the whole harmonic balancer/pulley assy.

HTH

Pete

ok yeh i was thinking its got something to do with the harmonic balancer are is don't spin straight its all over the place i'm gonna have a look at it again this weekend hopefully its an easy fix

I'd tip the harmonic balancer too, and hopefully it's just started to separate and not loose on the crank.

so with the harmonic balancers is it the bolt that normaly get loose on them i read on on of the other pages they come loose and people put a washer in there to stop it and just replace that woodworm key and it should fix it ay?

The rubber can separate and so the balancer needs replacing.

If it's come loose on the crank you need to really have a good look at the crank nose as it can stuff it badly.
That isn't good.

Oh, and BTW it's a woodruff key

haha i duno where im getting woodworm maybe thinking of something thats got nothing to do with engines at all haha sounds about right.

im going to be having another look at it this and see whats the go with it

os, if the installation is done correctly according to the manual, it is extremely rare for the crank bolt to come loose. Be aware that you need to lock the crank in place to loosen the bolt - unless it's already loose!

There is quite a bit of info on this topic. Use the search function to your advantage.

Pete