4.5!? Sounds like you've got an airlock..... 
I'll grab the Haynes and report back.
Right - from the Haynes capacities list, page 1A.2.
Cooling system:
1.1 and 1.4 - 6.5 litres
1.6 - 7 litres
1.8 and 2.0 - 7.5 litres
And no wonder the diesels take so long to warm up, no need for so much coolant in there tbh!
1.8 and 1.9 XUD - 9 litres
1.9 DW engine - 8.2 litres
2.0 (HDi) - 8.5 litres

I'll grab the Haynes and report back.

Right - from the Haynes capacities list, page 1A.2.
Cooling system:
1.1 and 1.4 - 6.5 litres
1.6 - 7 litres
1.8 and 2.0 - 7.5 litres
And no wonder the diesels take so long to warm up, no need for so much coolant in there tbh!

1.8 and 1.9 XUD - 9 litres
1.9 DW engine - 8.2 litres
2.0 (HDi) - 8.5 litres
