Thread: 300tdi fuel pump - advanced or retarded?

Hi Everyone,

My 300tdi Defender has a noticeable 'knock' at idle and low rpm. It is quite pronounced when cold, and improves when the D'Fer is up to running temperature.

Using a screwdriver as a stethoscope has shed no light. It doesn't appear to be related to the injectors or a particular cylinder. It knocks at about 4 beats per second around the top front of the engine.

Apart from this sound, the engine is perfect. No smoke (apart from the usual puff on start up) and it revs smoothly and powerfully across the rev range. The knock is less pronounced as the revs rise and disappears once you pass about 1600 rpm.

Vales clearances have been adjusted. Timing has been checked by a reputable LR specialist.

Swapping the injectors between the two vehicles yielded an instant, but short term improvement. While less pronounced, the knock is still there. I've tried all the solutions suggested by the "Google Dr" and on "You Tube", but am still at a loss.

I'm working on the theory that this is diesel knock caused by the injection pump timing being either advanced or retarded.

I've seen that when the timing pin is in place, there is a tiny bit of movement.

Is it possible that my timing is still a smidge in the wrong direction? What would be the impact if I time the engine by 'ear'? I used to do this on my old G60 Patrol (petrol).

And before you go there, yes I know you can't do this with the engine running!

Thanks,

Mathew

Thank you everyone for your comments. It looks like I might be on the right path then.

I think I'll start by swapping the pump from my Disco into the D'Fer. If the noise disappears that confirms the culprit.

All I need now is to get my hands on 2 x timing kits so I can remove the pumps without upsetting everything else!

Regards,

Mathew