I'm kind of surprised that the EVO has the old fashioned overflow recovery tank instead of the integrated/pressurized expansion tank you see on most new cars.

I noticed mine was about 3/4" lower than the cold fill line so I topped it up (to the line). After a couple days it looked about 1/4" low. I tmight not be anything since the ambient was cooler when I checked. I filled it a little higher than the line and I'll monitor it closely. I'm using normal green ethylene glycol.

Has anybody else found the need to add coolant?

 

i think there is a sponge in that tank right? Well im not sure where the coolant went in the first place but when you filled it up all the way and a day later it was at 3/4, i think most of it got soaked by that sponge. I may be thinking of a whole different tank all together.

 

my evo was losing coolant too, i went to the dealer and they say there was a coolant leak, maybe u should have urs check out