[Philip1972]

Its used a whole expansion tank full in a 15 miles drive.
Now, if its the head gasket, SURELY with it using that qty of water, there would be other symptoms? There are NO other symtoms-no steam out of the back, gauge is central and heater works.....

Couldnt get a new cap today-get one tomorrow.

(Have ordered a block test anyway, should be here soon)

 

[RYM]

I would advise you check all around the engine bay and underneath to see if you are losing coolant from a hose or the radiator:thumbsup

If it's not over heating then that's a good sign, I take it you've checked to see if there is a mayo type gunk on the oil dip stick?

That's a lot of water to be using and I'd seriously advise you don't drive it until you have found the cause and rectified:thumbsup

Have you topped up the water and checked to see if the level goes down?

 

[steve23002]

See how you get on with the coolant leak when you get the new cap Philip. Report back to us how it goes. :thumbsup

 

[Ronnie]

Have you bleed the cooling system?

How to bleed the cooling system.
1.Jack the front of the vehicle up onto stands as high as possible,
2.Turn the ignition on,engine off,heater on fan setting 1 and temperature fully hot,
3.Remove the rad cap/expansion cap,remove the bleed screw from the rad and IF you have them the bleed screw(s) from the thermostat housing/top hose, return pipe or EGR thermostat.
4.Fill the radiator up and keep pouring till there are no more air bubbles coming out from the bleeds, when good then install bleeds and tighten down(don't snap them),ensure the rubber O-rings/seals are still on the screws/on the bleed holes.
5.Suck some water out so it's not full to the brim, replace the cap and then start the car. Run her up and check for heat from the vents when warm and check if over heating still persists.
6.If good then check the water level again in the morning when cool.

 

[Philip1972]

I will be bleeding the system today along with a new cap.

I Just to satisfy my curiosity, why would an air lock make it use water?

Thanks

 

[markysurf]

I will be bleeding the system today along with a new cap.

I Just to satisfy my curiosity, why would an air lock make it use water?

Thanks

The AIR comes to the surface & is replaced with water, so your water level drops.

 

[Ronnie]

The AIR comes to the surface & is replaced with water, so your water level drops.

Correct, also if there are air pockets you get hot spots which causes the water to boil which makes more air pockets generally.