hpfp belt

[Saff]

Good evening all.

Just looking under the bonnet of my D4 4.2 tdi looking at the serpentine belt with a view to change when I replace my A/C compressor (another story).

I noticed that the High Pressure Fuel Pump is driven by a toothed belt. This is all news to me. Anyhow, I presume this has a replacement interval and was wondering what it might be in terms of time/mileage. Is anyone able to enlighten me and is it an absolute pig to do? It certainly looks to be given its location at the rear of the engine.

Cheers, Steve

[steamship]

Start from page 364 of the following PDF from the D4 Technical Info & Upgrades Sticky thread:

10-Service Manual 8-cylinder TDI engine (4 2 ltr 4-valve common rail).pdf

[Saff]

Hi Sean and many thanks.

It doesn't appear too bad after reading this, possibly a little awkward. What I can't seem to find is a schedule to replace the belt on an age/mileage basis. It seems that the belt is low-stressed therefore unlikely to fail but I can't help thinking that it would still deteriorate with time. Belt failure would not cause damage as such merely failure to proceed I can only assume owners don't bother changing it.

[steamship]

Originally Posted by Saff

What I can't seem to find is a schedule to replace the belt on an age/mileage basis.

Not an A8 or 4.2tdi, but this thread about a A6 3.0tdi raises the same question, with the responses being that there is 'no schedule', and in the event that it does break, all that happens is the car just stops. Someone suggested just doing a visual inspection, with another suggestion being that if the other belts are being replaced, you could add that one as well while you're there. A bit like replacing the thermostat when you're replacing the water pump.

https://www.audi-sport.net/xf/threads/213064/

Also, no reference whatsoever in the Maintenance document for the D4 A8:

27-Service Manual Maintenance.pdf