Hello everyone,

I am the original owner of this car.
Just a quick question. Recently noticed that for every 2-3K miles, I have to add a cup (like a cup of coffee) quantity of 50/50 coolant/water mixture.

Checked everywhere and no coolant leak seen:
- hoses
- radiator
- reservoir/cap
- underneath car
- all connections

The questions are:
1. This is Chicago summer and ambient temp can get to 70-90 deg F. Is it normal to see some degree of "evaporation" of coolant through the reservoir cap (The cap has a bypass valve to allow air to get out at certain pressure)?

2. What I am trying to rule out is a consumption of coolant into the engine (like a tiny cracked in engine or engine gasket leak) which is very expensive to repair. A normal slow loss of collant through evaporation, if true, is not an issue (similar to slow loss of air in the tires that once in a while you need to put more air in the tires).

TIA

cn
1998 V70 52K automatic miles
Chicago IL