slow coolant leak

[PHL08]

2008 E70 3.0si 98K miles...

I find I'm putting about 2 quarts of coolant in after around 1000 miles of driving and receiving the coolant warning. No evidence of leaking under the car after sitting for a while following a long drive. No visible evidence of leaking around the cooling tank or under the radiator. The radiator hose is new, no leakage evidence around it. The oil filter and coolant housing also has recently replaced gaskets and there is no leakage evident there either.

The indy shop that did that work 2 months ago, along with engine valve cover and gasket replacement due to oil leaking, inspected the coolant system and found no issues.

The electric pump was replaced right around the 50K mark. I know this is a known problem with my model and am starting to wonder if this is starting to go bad? I don't recall if this kind of coolant consumption is a sign of a failing pump, or if the pump just dies without any warning.

What other things might I check with respect to the high coolant consumption?