Needed to change my coolant today on the 2002 Multipla JTD. Found the plug under the radiator, unscrewed it, and what looks like a small amount of coolant dropped into the pan on the floor, 2 litres perhaps. The coolant tank (cap off) was empty at the end of this.

When I took the water pump off ( the reason for the change) there was no coolant in the head.

I can't find much anywhere about this on this fantastic forum or the web.

I can't see any obvious bleed nipples. Will search harder again tomorrow.
The return pipe and the coolant tank are very high, above the engine. Am I right in thinking that this is a self bleeding system ?

Did I empty the whole system through this low point drain plug or are there parts of the system still full of blue liquid ? I am surprised at the small quantity that came out. I don't like the idea of mixing two different fluid brands with the risk of gunk.

I have poured new ELF -35°C ready mix yellow cooling fluid into the coolant tank, under 2 litres and have not started the engine yet...

Any comments on this subject would be very welcome. It all seems too simple... I am worried about airlocks, and heater problems...

Well, I found two bleed nipples on top of the radiator hidden under the plastic cover that covers the top of the radiator, alot of air came out of those two. It only take two screws to get that cover off. Then there is a bleed nipple on the pipe that goes through the firewall to the heater, that weeped fluid straight away. Can't see any others. Yet...

The difference in fluid level in the coolant tank is about a big tea mug's worth. (No I didn't use my tea mug.)

Is this an explanation for all those wimpy heaters out there... not enough bleeding. Those nipples under ontop of the radiator are hidden and if you don't know about it you might leave alot of air in the system.

Any comments sports fans ?