mornin
always useful to add year model rhd? petrol? etc details of your van in your signature - so that peeps can get a better context of what your issues might be -
have you got someone else to switch off the van whilst yr standing next to engine bay to try and narrow down where the source of the gurgle is? does it sound / smell like coolant? petrol?
my van doesn't do this - but others might -
not sure 'normal' and 'van' belong on the same sentence!

Owner of a red T25 fixed hi top campervan - colour - spikey red - petrol - water cooled - 1.9 dg engine rhd - 1990 g reg n still going strong!-