LPG V8 P38 usin water -head seems ok - Any advise

Hi,
I have a 2000 P38 4.0 v8. She is using some water - not loads but needs toppin up every few weeks. I dont do loads of miles. I dont think shes mixing her drinks but after owning an old classic - once bitten twice an idiot. Is it normal for them to drink a little water?
Being a p38 - I have a couple of other problems but none to serious (IHOPE)

my 4.6 went the same way, after checking everything else i put it down to the block !!!

sure enough after rebuilding the engine with a new block the problems gone, its been ok now for the last 5 years.

I assume you've had a good wash down and checked for leaks?

Thanks, Yeah I've checked out for leaks - My nephew (pet mechanic) seems to think its fine - but I've had rangie head problems before. Do some just use some water?

my 3.9 started using water turned out to be the block had a crack down one of the bores checking around found its not uncommon only solution new short motor