Cambelt should be changed every 40k on this particular model. The Dealers tend to advise changing the water pump at 80k but from experience I would do the water pump at 40k. If you go to an Independant they will usually get a whole kit and can usually do the job in about 3 hours.

My 2006 Z16 XEP Zafira (as opposed to Z16 XE) is 100,000 miles or 10 years cam belt change intervals - confirmed by my local VX dealer. The Z16 XEP water pump is driven off an auxiliary belt I believe so up to you if you have water pump and belt changed at same time.

My belt is on 85,000 and I must admit I'm getting a bit reticent about going beyond 90,000 miles without changing.

See last post at bottom here:

http://www.cavweb-forums.co.uk/showthread.php?161091-Astra-mk4-tiing-belt-change

Edited by Victorbox on 31/08/2010 at 22:29

the reccomended spec on these is indeed 40,000 miles for a cambelt change. I would do the water pump at the same time regardless wether it is driven by the aux belt or cam belt. The aux belt needs off to do the cam belt anyway so its better to change the water pump. Mine is due this year also and I have got a genuine vauxhall kit and water pump for a total of £78, whcih i think is good value.

I have found these are good engines if you look after them, I had a astra with a Z14XE and now have a zafira with a Z16XE engine, and cannot yet touch wood fault them both, but thye have been looked after and serviced properly.