I posted this on the T4/T5 forum but have received no replies so far. Can anyone help here please?

I have just become very worried because I realise that my recently purchased 1999 T4 with 83,000 miles still has its original water pump. I have spent some time trying to decipher the German T4 Wiki translation relating to known problems and have found that the water pump in my engine number falls into their "death list" category

The problem water pump has 18 teeth and the upgraded pump designed to cope better with the load on the 2.5 tdi's has 20 teeth.
The new pump after Nov 1999 is part no. 074 121 005NX which changed again in Oct 2006 to 074 121 005MX.

From what I have read it is only on petrol engines that the fitting of a new camshaft pulley/sprocket is also required to match the water pump.
So am I correct in assuming, based on all I have found out so far, that the new 20 tooth pump was designed to work with the existing camshaft pulley on an ACV engine???

I need to sort this immediately so any advice is greatly appreciated.

Paul.