Hi the GF has a Clio 1.2 8v 1998 is seems to lose about the entire expansion tank of water in 2-3 days. It has been checked for leaks and nothing is obvious. I have replaced the waterpump & thermostat as well and pretty sure there are no air locks as there are 2 bleed points and all pipes get hot including the radiator, The fan cuts in and out OK. The car drives normally and no excessive water out of the exhaust.

I'm at my wits end with this now so looking for any ideas on other causes

Thanks

if there's no visable leaks external or in the car(heater matrix ) the only other way it's losing it will be head gasket, I have a changed a few head gaskets on clios over the years....

Has had a pressure leak down test when cold? you can't find small leaks on a hot system as the coolant flashes straight to steam which is invisible.

Had a similar thing on our land rover discovery once and it turned out to be the smallest of pinholes in a core plug right at the rear of the head. Absolute bi**h to find!!

Early MK2 Clios with the D7F engine were common for the headgasket splitting between the no.1 cylinder (g/box end) and the coolant passage hole at the front of the engine. Common issue is also the metal pipe coming out of the back of the water pump rotting but this was more the early 1.4 8v (E7J) but have seen it on the 1.2 8v aswell.

If you do change the head gasket remember renault didn't put much meat on the bottom of the heads in that era so it can be touch and go regards to skimming.

Shaun

The head gasket has been changed and there was no sign of any leak on that gasket at all.

It hasn't had a leakdown test yet,

I've noticed that even after the car has been sat for 4 hours plus and the car feels cold that when you take of the expansion tank top there is a release of pressure and the coolant level rises, never enough to go back to normal thou. I am very careful to make sure i bleed the system but this is very frustrating now