c5 coolant loss

[sonoramicommando]

hi all,

my c5's dumped about a litre of coolant after i drove to my mum's place - today and a week ago.
it's about 15 minutes of 50kph town driving (not that much of stop start) and 10 minutes of 50-70kph of hilly winding road.
if the water temp gauge is to be believed, it's sitting at dead centre (as it does most of the times, except for morning starts).
my commuting route is 10-15 minutes on motorways and 5 odd minutes 50kph zone with hardly any stop & start situation.
i have been commuting for the past 5 months with no problem whatsoever. longest trip i took in the car is around 50 minutes at 110-120kph on open roads.
both times it dumped coolant, it was parked with one side of the car higher, around 30-40° i'd say.
the first time, the passenger side was on the lower and today it was the other way around but dumped the liquid all the same.
i couldn't quite figure out where it was coming from but it was coming out of the driver's side bumper corner, just in front of the tyre.
what do you guys think? do i have a problem here?
im guessing its one of the following:
a) the parking attitude
b) expansion chamber and/or hose(s)
c) radiator

cheers,
sam

[citroenxm]

expansion bottle is on the drivers side so there will be water pipes behind the wing on that side... try removing the inner wing plastic trim and have a look at the pipes under there sounds like one is leaking somewhere...

[sonoramicommando]

yes - i did notice that a rubber hose is going down under the wing.
funny thing is i've never seen it dumping on a straight up or downhill and level ground either.
going to mum's place tomorrow and the day after as well - interested to see if it happens again.

[sonoramicommando]

does the cap let coolant escape if the level exceeds the volume of the expansion tank? i'm pretty sure it's coming out of there.
i filled it up to max in the morning (maybe a bit more, because the car wasn't quite level) and caught a few drops coming out somewhere on top of the tank with car parked nose up.
the fan kicks in at around 97 and cuts out at 93 after driving and sitting at idle, which is what's supposed to happen according to lexia.

[Clogzz]

The cap lets the excess coolant escape.
The tank can’t be filled to the brim, it must hold a volume of air to allow the coolant to expand.
Mine’s normal level looks like almost empty.
If I add any, it will squirt it out.

I drive with the cap loose to prevent the circuit from pressurising.
Last month, 840 km trip from Sydney to Queensland with stretches at 35ºC, and the temperature gauge stayed in the middle with no coolant loss.