Coolant Loss Astra 1.6 8v

[ffzetecs]

Incurring some coolant loss on my 2001 Astra; can't spot any obvious leaks but having to top up every couple of weeks.

Can't see any smoke on start up either.

Any ideas appreciated.

[Crafty_]

Oil clean ?

Compression test ?

My memory is a bit dodgy, but may be failing inlet gasket - don't remember that exact engine.

Worst case scenario is head gasket.