Please Help... Knocking PD TDI

shifty

Guest
I also have this knocking noise. It appeared last week not long after my custom map, and as the injectors are the only things to be carried over from my old engine (new motor only done 2k now) they were immediately suspect. No faults on VAG COM, but one of the injector readings is way out.....hopefully by me not driving it after making the discovery damage is confined to the one injector. New ones on the way, only time will tell.

The early signs of this happening are a ticking noise, audible particularly when at idle after starting from cold. This has now turned to a mechanical sounding knocking noise, but apparently is the derv equivalent of pinking and is in fact known as diesel knock. Something to do with overfuelling from the faulty unit.
 

sssstew

Editing your spelling
diesel knock occurs because of the immediate and sudden ignition of the fuel once injected, this has been improved with modern diesels with the use of pre and post injection to slow build up and slow down the main ingition (the main bang). A faulty injector would make sense in this case as it would be injecting incorrect quantities at possibly incorrect times, although the times are set from the cam lobe.
 

devonutopia

fabia-lous
Mar 30, 2004
1,200
1
Exmouth / Exeter
I have a genuine 1.9 ASZ cam on fleabay if anyone with pd130/pd150 is aware their cam is damaged and in need of replacement. I'm a little worried about mine now, but she seems to run well on Millers XFE-PD oil so I'll not be too concerned for now. :)
 
Lecatona HPFP (High-pressure Fuel Pump Upgrades)