T4 TDi ACV engine noise

**farmsyncro** · 13-02-2018, 10:33 AM

Hi all,

Our TDI syncro 2.5 ACV engine has suddenly developed a horrible engine noise.
It was parked one day normally then the next morning straight away it sounds like a chaff cutter. The general noise level has gone up heaps as just clatter. Like "normal" diesel noise just lots more of it. Not a specific rattle or heavy enough for a big or little end or a piston noise, more like really noisy tappets.

Yes it has oil in it and within service period.

Discussion with Jets (Cheers Jets!!) suggested:
checking fuel for water (clean) I did refill tank at my usual servo 300km before problem started. I would expect a dodgy fuel load to be obvious within minutes of filling.
Check Injection timing on VagCom - this revealed "timing too far advanced to measure" and fault code 17656 Injection Start regulation. I have since adjusted the timing to correct this & found everything as it should be IE tight & secure. The fault code was cleared and has not reappeared.

I have checked cam belt & tensioner as I had a noise (different) here before. I have checked injection pump belt & rollers & these are OK

Test driving the car after the timing adjust shows the performance to be fine but the tappety rattle is intense.

Any other ideas?

Thanks

FarmSyncro